ICM: Name mappings parameters

[Nuttymoon]

[Nuttymoon]

Since Solidity 0.8.18, developers can utilize named parameters in mappings. This means mappings can take the form of mapping(KeyType KeyName? => ValueType ValueName?). This updated syntax provides a more transparent representation of the mapping's purpose.

Throughout the codebase, there are multiple mappings without named parameters. For instance:

• The tokenToHomeBridge state variable in the AvalancheICTTRouter contract.

• The tokenRemoteChainToRemoteBridge state variable in the AvalancheICTTRouter contract.

Consider adding named parameters to the mappings to improve readability and maintainability of the code.