🔧 Add `CREATE` Tests

[pcaversaccio]

🕓 Changelog

This PR adds the tests for all CREATE functions in CreateX; namely:

• function deployCreate(bytes) payable returns (address)
• function deployCreateAndInit(bytes,bytes,tuple(uint256,uint256)) payable returns (address)
• function deployCreateAndInit(bytes,bytes,tuple(uint256,uint256),address) payable returns (address)
• function deployCreateClone(address,bytes) payable returns (address)
• function computeCreateAddress(uint256) view returns (address)
• function computeCreateAddress(address,uint256) view returns (address)

I also slightly refactored the test directory by moving the corresponding contracts to appropriate sub-directories. Please note that this PR is rebased on the PR https://github.com/pcaversaccio/createx/pull/13. Finally, I also removed the now obsolete CreateX.t.sol test contract.

Eventually, I created a CreateX logo and added to the README:

PR Checklist

• [ ] Because this PR includes a bug fix, relevant tests have been included.
• [x] Because this PR includes a new feature, the change was previously discussed in an issue or in the discussions section. (See https://github.com/pcaversaccio/createx/issues/10.)
• [ ] I didn't do anything of this.

🐶 Cute Animal Picture

[pcaversaccio]

@mds1 this PR is ready for review. The reason why I didn't include all the CREATE functions is that otherwise, it becomes too big.