refactor: use custom error for `onlyOwner` and `address(0)` check

[CJ42]

What does this PR introduce?

⚠️ BREAKING CHANGES

• Fixed: minimum solc version required for ERC725Y is now 0.8.4 because of the use of custom errors: https://github.com/ethereum/solidity/releases/tag/v0.8.4
• Refactor: minimum solc version required for ERC725X and ERC725 is now 0.8.5 because of the use bytes to bytesN conversion: https://github.com/ethereum/solidity/releases/tag/v0.8.5

📦 Build

• Increase minimum solc compiler version because of full usage of custom error (currently states pragma solidity ^0.8.0

⚡️ Performance

Replace revert reason strings with custom errors for OwnableUnset and address(0) check on transferOwnership(), constructor and initialize(address) functions.

This reduces the deployment cost of an ERC725 smart contract by -58,427 gas.

PR Checklist

• [x] Wrote Tests
• [x] Wrote Documentation
• [x] Ran npm run lint && npm run lint:solidity
• [x] Ran npm run format (prettier)
• [x] Ran npm run build
• [x] Ran npm run test

[CJ42]

Before

·----------------------------------------------------------------------|----------------------------|-------------|-----------------------------·
| Solc version: 0.8.17 · Optimizer enabled: false · Runs: 200 · Block limit: 30000000 gas │
·······································································|····························|·············|······························
| Methods │
···············|·······················································|·············|··············|·············|···············|··············
| Contract · Method · Min · Max · Avg · # calls · usd (avg) │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725 · execute(uint256,address,uint256,bytes) · 34726 · 127088 · 47401 · 113 · - │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725 · executeBatch(uint256[],address[],uint256[],bytes[]) · 60485 · 155455 · 92070 · 16 · - │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725 · renounceOwnership() · 31296 · 31341 · 31319 · 4 · - │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725 · setData(bytes32,bytes) · 32983 · 8566933 · 1551068 · 17 · - │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725 · setDataBatch(bytes32[],bytes[]) · 35151 · 8569119 · 1471557 · 18 · - │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725 · transferOwnership(address) · 32082 · 32104 · 32097 · 6 · - │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725Init · initialize(address) · 51762 · 51784 · 51762 · 122 · - │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725X · execute(uint256,address,uint256,bytes) · 31954 · 124204 · 44619 · 113 · - │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725X · executeBatch(uint256[],address[],uint256[],bytes[]) · 57611 · 152526 · 89181 · 16 · - │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725X · renounceOwnership() · - · - · 23677 · 2 · - │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725X · transferOwnership(address) · - · - · 29235 · 2 · - │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725Y · renounceOwnership() · - · - · 23678 · 2 · - │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725Y · setData(bytes32,bytes) · 30252 · 8561709 · 1547892 · 17 · - │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725Y · setDataBatch(bytes32[],bytes[]) · 32396 · 8563865 · 1468380 · 18 · - │
···············|·······················································|·············|··············|·············|···············|··············
| ERC725Y · transferOwnership(address) · - · - · 29213 · 4 · - │
···············|·······················································|·············|··············|·············|···············|··············
| Deployments · · % of limit · │
·······································································|·············|··············|·············|···············|··············
| ERC725 · - · - · 2454031 · 8.2 % · - │
·······································································|·············|··············|·············|···············|··············
| ERC725Init · - · - · 2659411 · 8.9 % · - │
·······································································|·············|··············|·············|···············|··············
| ERC725X · - · - · 1892377 · 6.3 % · - │
·······································································|·············|··············|·············|···············|··············
| ERC725XInit · - · - · 2103358 · 7 % · - │
·······································································|·············|··············|·············|···············|··············
| ERC725Y · - · - · 1197840 · 4 % · - │
·······································································|·············|··············|·············|···············|··············
| ERC725YInit · - · - · 1403187 · 4.7 % · - │
·----------------------------------------------------------------------|-------------|--------------|-------------|---------------|-------------·

After

·----------------------------------------------------------------------|----------------------------|-------------|-----------------------------·
|                         Solc version: 0.8.17                         ·  Optimizer enabled: false  ·  Runs: 200  ·  Block limit: 30000000 gas  │
·······································································|····························|·············|······························
|  Methods                                                                                                                                      │
···············|·······················································|·············|··············|·············|···············|··············
|  Contract    ·  Method                                               ·  Min        ·  Max         ·  Avg        ·  # calls      ·  usd (avg)  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725      ·  execute(uint256,address,uint256,bytes)               ·      34726  ·      127088  ·      47401  ·          113  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725      ·  executeBatch(uint256[],address[],uint256[],bytes[])  ·      60485  ·      155455  ·      92070  ·           16  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725      ·  renounceOwnership()                                  ·      31296  ·       31341  ·      31319  ·            4  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725      ·  setData(bytes32,bytes)                               ·      32983  ·     8267752  ·    1498271  ·           17  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725      ·  setDataBatch(bytes32[],bytes[])                      ·      35151  ·     8269937  ·    1421694  ·           18  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725      ·  transferOwnership(address)                           ·      32082  ·       32104  ·      32097  ·            6  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725Init  ·  initialize(address)                                  ·      51762  ·       51784  ·      51762  ·          122  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725X     ·  execute(uint256,address,uint256,bytes)               ·      31954  ·      124204  ·      44619  ·          113  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725X     ·  executeBatch(uint256[],address[],uint256[],bytes[])  ·      57611  ·      152526  ·      89181  ·           16  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725X     ·  renounceOwnership()                                  ·          -  ·           -  ·      23677  ·            2  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725X     ·  transferOwnership(address)                           ·          -  ·           -  ·      29235  ·            2  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725Y     ·  renounceOwnership()                                  ·          -  ·           -  ·      23678  ·            2  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725Y     ·  setData(bytes32,bytes)                               ·      30252  ·     8262625  ·    1495113  ·           17  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725Y     ·  setDataBatch(bytes32[],bytes[])                      ·      32396  ·     8264780  ·    1418533  ·           18  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  ERC725Y     ·  transferOwnership(address)                           ·          -  ·           -  ·      29213  ·            4  ·          -  │
···············|·······················································|·············|··············|·············|···············|··············
|  Deployments                                                         ·                                          ·  % of limit   ·             │
·······································································|·············|··············|·············|···············|··············
|  ERC725                                                              ·          -  ·           -  ·    2395604  ·          8 %  ·          -  │
·······································································|·············|··············|·············|···············|··············
|  ERC725Init                                                          ·          -  ·           -  ·    2601464  ·        8.7 %  ·          -  │
·······································································|·············|··············|·············|···············|··············
|  ERC725X                                                             ·          -  ·           -  ·    1833965  ·        6.1 %  ·          -  │
·······································································|·············|··············|·············|···············|··············
|  ERC725XInit                                                         ·          -  ·           -  ·    2045382  ·        6.8 %  ·          -  │
·······································································|·············|··············|·············|···············|··············
|  ERC725Y                                                             ·          -  ·           -  ·    1135735  ·        3.8 %  ·          -  │
·······································································|·············|··············|·············|···············|··············
|  ERC725YInit                                                         ·          -  ·           -  ·    1345233  ·        4.5 %  ·          -  │
·----------------------------------------------------------------------|-------------|--------------|-------------|---------------|-------------·