Rename Signatory to Signer

[hanzel98]

📝 Description

Rename signatory to signer in MetaMaskSmartAccount configuration to improve developer experience and API clarity.

🔄 What Changed?

List the specific changes made:

• Renamed signatory parameter to signer in ToMetaMaskSmartAccountParameters type
• Updated all type definitions: SignatoryConfigByImplementation → SignerConfigByImplementation, InternalSignatory → InternalSigner, etc.
• Renamed all config types: WalletSignatoryConfig → WalletSignerConfig, AccountSignatoryConfig → AccountSignerConfig, HybridSignatoryConfig → HybridSignerConfig, MultiSigSignatoryConfig → MultiSigSignerConfig, WebAuthnSignatoryConfig → WebAuthnSignerConfig, Stateless7702SignatoryConfig → Stateless7702SignerConfig
• Renamed signatory.ts file to signer.ts and updated all imports
• Updated function names: resolveSignatory → resolveSigner, resolveSignatoryFromWalletConfig → resolveSignerFromWalletConfig, etc.
• Updated all variable names throughout codebase from signatory to signer
• Updated all test files to use new terminology
• Updated documentation in README.md and test descriptions
• Updated e2e test files in delegator-e2e package
• Cleaned up old unused signatory.ts file

🚀 Why?

Explain the motivation behind these changes:

• Improve developer experience by using more familiar and intuitive terminology
• signer is more commonly understood in the web3 ecosystem than signatory
• Reduce cognitive load for developers integrating with MetaMaskSmartAccount
• Align with industry standard naming conventions

🧪 How to Test?

Describe how to test these changes:

• Manual testing steps:

1. Run yarn lint to ensure code formatting is correct
2. Run yarn test to verify all tests pass
3. Run yarn build to ensure successful compilation

• Automated tests added/updated
• All existing tests pass (587 tests passing)

⚠️ Breaking Changes

List any breaking changes:

• Breaking changes (describe below):
  • API Breaking Change: The signatory parameter in ToMetaMaskSmartAccountParameters is now signer
  • Type Breaking Change: All *SignatoryConfig types are now *SignerConfig types
  • Import Breaking Change: Import from ./signer instead of ./signatory
  • Function Breaking Change: resolveSignatory is now resolveSigner

📋 Checklist

Check off completed items:

• Code follows the project's coding standards
• Self-review completed
• Documentation updated (if needed)
• Tests added/updated
• Changelog updated (if needed)
• All CI checks pass

🔗 Related Issues

Link to related issues:
Closes #267 https://app.zenhub.com/workspaces/readable-permissions-67982ce51eb4360029b2c1a1/issues/gh/metamask/delegator-readable-permissions/267

📚 Additional Notes

This is a comprehensive breaking change that affects the public API. While the functionality remains exactly the same, any code using the MetaMaskSmartAccount configuration will need to update:

1. Change signatory: to signer: in configuration objects
2. Update any type imports from *SignatoryConfig to *SignerConfig
3. Update any direct usage of resolveSignatory to resolveSigner