feat: add discoverability methods

[MoMannn]

📝 Description

This PR adds ERC-7715 discoverability methods (wallet_getSupportedExecutionPermissions and wallet_getGrantedExecutionPermissions) to the smart-accounts-kit package, enabling applications to query wallet capabilities and previously granted permissions. It also includes refactoring to improve code organization and maintainability.

🔄 What Changed?

List the specific changes made:

• Added erc7715GetSupportedExecutionPermissionsAction to query supported permission types, chain IDs, and rule types from the wallet
• Added erc7715GetGrantedExecutionPermissionsAction to retrieve all previously granted permissions that haven't been revoked
• Extended erc7715ProviderActions with getSupportedExecutionPermissions and getGrantedExecutionPermissions methods
• Extracted shared types into a new erc7715Types.ts file (MetaMaskExtensionSchema, MetaMaskExtensionClient, result types)
• Moved utility functions (isDefined, assertIsDefined, toHexOrThrow) from the action file to utils.ts for reuse
• Updated MetaMaskExtensionSchema to include the new RPC method definitions

🚀 Why?

Explain the motivation behind these changes:

• Applications need to discover what permissions a wallet supports before requesting them, improving UX by preventing unsupported permission requests
• Applications need to query existing granted permissions to avoid duplicate requests and to display permission status to users
• Extracting types into a dedicated file creates a cleaner dependency graph and makes the code easier to maintain
• Moving utility functions to utils.ts enables reuse across the codebase and follows DRY principles

🧪 How to Test?

Describe how to test these changes:

• Manual testing steps:

• Automated tests added/updated
• All existing tests pass

⚠️ Breaking Changes

List any breaking changes:

• No breaking changes
• Breaking changes (describe below):

📋 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 #
Depends on: MetaMask/metamask-extension#39176

📚 Additional Notes

Any additional information, concerns, or context:

---

Note

Adds ERC‑7715 discoverability to smart-accounts-kit and refactors shared types/utilities.

• New actions: erc7715GetSupportedExecutionPermissionsAction and erc7715GetGrantedExecutionPermissionsAction (RPC: wallet_getSupportedExecutionPermissions, wallet_getGrantedExecutionPermissions, retryCount: 0)
• Extends erc7715ProviderActions with getSupportedExecutionPermissions and getGrantedExecutionPermissions
• Extracts MetaMaskExtensionSchema, MetaMaskExtensionClient, and result types to src/actions/erc7715Types.ts; updates exports in index.ts
• Moves isDefined, assertIsDefined, toHexOrThrow into src/utils.ts and updates erc7715RequestExecutionPermissionsAction to use them
• Adds unit tests for the two new actions and provider extensions

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[V00D00-child]

Looking good! Left some minor comments on using revised 7715 types, and there is a small merge conflict that needs resolution.

[mj-kiwi]

LGTM