chore: cleaned up and reorganized smart contracts and tests folders (#624)

[quiet-node]

Description: This PR mainly cleans up and reorganizes the folders. Below is a list of tasks done:

• [x] reorganized contracts/ folder => moved and grouped contracts under folders that makes more sense
• [x] reorganized tests/ folder to match up with the layout of the contracts/ folder
• [x] formatted the codebase with prettier to keep the code style consistent among files
• [x] updated SPDX-License-Identifier for all contracts to use Apache-2.0
• [x] recompiled all smart contracts to make sure all artifact files (.json files) are committed to the git tree
• [x] updated artifacts and contract assets path for the Dapp Playground to make sure prerequisite-check pass for the Dapp Playground
• [x] updated all the unit tests tag names to make sure all these files have the appropriate tag names (@solidityequiv1, @solidityequiv2, @solidityequiv3, @OZ)
• [x] added a new group of tag name for yul/ folder, called @yulequiv and added it to CI dispatch task among with @solidityquiv and @OZ
• [x] added contract names to Constants.Contract variables

Related issue(s):

Fixes #624

Notes for reviewer:

Checklist

• [x] Documented (Code comments, README, etc.)
• [x] Tested (unit, integration, etc.)

[github-actions[bot]]

Test Results

  19 files  +  6    88 suites  +19   11m 11s :stopwatch: + 3m 7s 240 tests +  5  231 :heavy_check_mark: +  2  6 :zzz: ±0  3 :x: +3  297 runs  +62  284 :heavy_check_mark: +55  8 :zzz: +2  5 :x: +5 

For more details on these failures, see this check.

Results for commit d0cda6ae. ± Comparison against base commit ee8db364.

This pull request removes 82 and adds 87 tests. Note that renamed tests count towards both.

``` Should NOT allow a non-operator to transfer tokens to another account ‑ @OZERC1155 Upgradable Vaults Tests Should NOT allow a non-operator to transfer tokens to another account Should NOT be able to change the current proxy admin if the caller is not an admin ‑ @ERC1967Upgrade Upgradable Vote Tests Proxy Contract tests Should NOT be able to change the current proxy admin if the caller is not an admin Should NOT burn insufficient amount of token ‑ @OZERC1155 Upgradable Vaults Tests Should NOT burn insufficient amount of token Should NOT transfer the ownership to another account if the caller is not owner ‑ @OZERC1155 Upgradable Vaults Tests Should NOT transfer the ownership to another account if the caller is not owner Should allow an operator to transfer a token to another account ‑ @OZERC1155 Upgradable Vaults Tests Should allow an operator to transfer a token to another account Should allow an operator to transfer tokens in batch to another account ‑ @OZERC1155 Upgradable Vaults Tests Should allow an operator to transfer tokens in batch to another account Should be able to change the current proxy admin to a new address ‑ @ERC1967Upgrade Upgradable Vote Tests Proxy Contract tests Should be able to change the current proxy admin to a new address Should be able to get the predefined ERC1967 ADMIN_SLOT ‑ @ERC1967Upgrade Upgradable Vote Tests Proxy Contract tests Should be able to get the predefined ERC1967 ADMIN_SLOT Should be able to get the predefined ERC1967 IMPLEMENTATION_SLOT ‑ @ERC1967Upgrade Upgradable Vote Tests Proxy Contract tests Should be able to get the predefined ERC1967 IMPLEMENTATION_SLOT Should be able to mint a new token ‑ @OZERC1155 Upgradable Vaults Tests Should be able to mint a new token … ``` ``` Should NOT allow a non-operator to transfer tokens to another account ‑ @OZERC1155 Tests Should NOT allow a non-operator to transfer tokens to another account Should NOT be able to change the current proxy admin if the caller is not an admin ‑ @OZERC1967Upgrade Upgradable Vote Tests Proxy Contract tests Should NOT be able to change the current proxy admin if the caller is not an admin Should NOT burn insufficient amount of token ‑ @OZERC1155 Tests Should NOT burn insufficient amount of token Should NOT transfer the ownership to another account if the caller is not owner ‑ @OZERC1155 Tests Should NOT transfer the ownership to another account if the caller is not owner Should allow an operator to transfer a token to another account ‑ @OZERC1155 Tests Should allow an operator to transfer a token to another account Should allow an operator to transfer tokens in batch to another account ‑ @OZERC1155 Tests Should allow an operator to transfer tokens in batch to another account Should be able to change the current proxy admin to a new address ‑ @OZERC1967Upgrade Upgradable Vote Tests Proxy Contract tests Should be able to change the current proxy admin to a new address Should be able to get the predefined ERC1967 ADMIN_SLOT ‑ @OZERC1967Upgrade Upgradable Vote Tests Proxy Contract tests Should be able to get the predefined ERC1967 ADMIN_SLOT Should be able to get the predefined ERC1967 IMPLEMENTATION_SLOT ‑ @OZERC1967Upgrade Upgradable Vote Tests Proxy Contract tests Should be able to get the predefined ERC1967 IMPLEMENTATION_SLOT Should be able to mint a new token ‑ @OZERC1155 Tests Should be able to mint a new token … ```

:recycle: This comment has been updated with latest results.