Implement: Replace Address.isContract

[zarifpour]

Description

Openzeppelin has removed the function isContract in V5 due to potential misuse. It is recommended to use address.code.size > 0 instead of isContract.

See:

• Remove isContract due to potential misuse OpenZeppelin/openzeppelin-contracts#3417
• Remove Address.isContract OpenZeppelin/openzeppelin-contracts#3945

Action Items

• Replace every instance of isContract with address.code.size > 0