chore: update MADs precompile contract

[shekohex]

This pull request includes several changes focusing on the MultiAssetDelegation interface and related contracts. The main updates involve adding custom selectors to functions, modifying the balance retrieval logic, and updating the mock contract for testing purposes.

Interface Updates:

• Added @custom:selector annotations to all functions in the MultiAssetDelegation interface to specify their selectors. [1] [2] [3]

Balance Retrieval:

• Introduced a new internal function _balanceOf in TangleMultiAssetDelegationWrapper to get the current balance of a delegator.
• Updated the totalAssets function in TangleLiquidRestakingVault to use _balanceOf instead of asset.balanceOf.

Mock Contract Updates:

• Modified MockMultiAssetDelegation to include a constructor that accepts an ERC20 token and added functions to retrieve balances. [1] [2] [3]
• Updated the MockMultiAssetDelegation contract to track delegated amounts and return balances accordingly.

Testing Updates:

• Updated the TangleLiquidRestakingVaultTest to initialize MockMultiAssetDelegation with a base token.

Closes #2

[shekohex]

Needs: tangle-network/tangle#885

[github-actions]

LCOV of commit 2721e50 during CI #13

Summary coverage rate:
  lines......: 81.1% (215 of 265 lines)
  functions..: 66.1% (41 of 62 functions)
  branches...: 68.4% (13 of 19 branches)

Files changed coverage rate:
                                           |Lines       |Functions  |Branches    
  Filename                                 |Rate     Num|Rate    Num|Rate     Num
  ===============================================================================
  src/TangleLiquidRestakingVault.sol       |18.5%    135| 100%    19|    -      0
  src/TangleMultiAssetDelegationWrapper.sol|37.0%     27| 0.0%    10|    -      0
  test/mock/MockMultiAssetDelegation.sol   |49.0%     51| 0.0%    11|    -      0