feat: skip signature length encoding on final sig and add type safety

[jaypaik]

• Updated SparseCalldataSegmentLib.sol to include updates from feat: skip signature length encoding on final sig alchemyplatform/modular-account#215.
• Updated ValidationConfigLib.sol to include updates from test: port library tests and add type safety alchemyplatform/modular-account#208

[octane-security-app]

Summary by Octane

New Contracts

• ModuleSignatureUtils.sol: ModuleSignatureUtils encodes modular account validation signatures, supporting pre-hooks and custom validation data.

Updated Contracts

• SparseCalldataSegmentLib.sol: The smart contract now includes segment indices, omits segment body extraction, and directly handles segment validation, enhancing segment management.
• ValidationConfigLib.sol: Introduced ValidationFlags type for enhanced flag handling in smart contract validation functions.
• ReturnDataModuleMocks.sol: Updated the smart contract's validation method and enhanced signature handling by integrating ModuleSignatureUtils and ModuleEntityLib.
• AccountTestBase.sol: Enhanced smart contract with added signature utilities, removing redundant signature encoding functions.

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🔗 Commit Hash: c823956