feat(contracts): implement ERC-7579 account config interfaces

Add IERC7579AccountConfig and IERC7579ModuleConfig implementation to
MpcSmartAccount for modular smart account interoperability.

Changes:
- Implement accountId(), supportsExecutionMode(), supportsModule()
- Add installModule/uninstallModule for all 4 module types
- Add module tracking storage (validators, executors, hooks, fallbacks)
- Implement isModuleInstalled() with context support for fallbacks
- Add module enumeration getters (getInstalledValidators, etc.)
- Enhance fallback() to route to installed fallback handler modules
- Support execution modes: default, batch, try (delegatecall disabled)

This enables dynamic installation of ERC-7579 compliant modules like
session key validators, spending limit hooks, and recovery executors.

Author: Kazopl