feat: move custom errors from libraries to interfaces for external accessibility (#57)

[ogazboiz]

This PR moves custom errors from internal libraries to public interfaces, making them accessible to external users.

Fixes #57

Problem:
Custom errors were buried in libraries. UI developers had no canonical access to these errors. They had to reimplement errors elsewhere, introducing inconsistencies and making Compose adoption difficult.

Solution:
Created interface files with all custom errors in src/interfaces/ directory. Updated libraries and facets to use local error definitions instead of importing from interfaces.

Changes:
• Created IERC20.sol with all ERC20 custom errors
• Created IERC721.sol with all ERC721 custom errors
• Created IERC721Enumerable.sol with all ERC721Enumerable custom errors
• Created IERC173.sol with all ERC173 custom errors
• Updated all libraries to use local error definitions
• Updated all facets to use local error definitions
• Added proper author attribution to all interface files

Benefits:
• External users get direct access to custom errors via interfaces
• UI developers have canonical error definitions
• Follows industry standard of declaring errors in interfaces
• Maintains full backward compatibility
• All tests pass

Technical Details:
All error references use the original format (e.g., ERC20InsufficientBalance(...)). Interface files are standalone for external users only. All internal code uses local error definitions.

cc: @mudgen

[mudgen]

I am sorry, we are not using the author natspec tag.

[ogazboiz]

I will remove that instead I thought I removed that
@mudgen

[mudgen]

Thanks!

[ogazboiz]

@mudgen i have remove that

[mudgen]

@ogazboiz I see that your commits show up in the contributors section now. That's great.
https://github.com/Perfect-Abstractions/Compose/graphs/contributors