Refactor: Add setTrustedRemoteAddress/getTrustedRemoteAddress functionality

[CruzMolina]

• build: rm obsolete .gitkeep
• refactor: expand IAssetHandler to include setLayerZeroTrustedRemoteAddress functionality
• doc: improve explicitness of setLayerZeroChainIdDestination NatSpec
• refactor: integrate setLayerZeroTrustedRemoteAddress into L1AssetHandler
• refactor: integrate setLayerZeroTrustedRemoteAddress into L2AssetHandler
• build: add setLayerZeroTrustedRemoteAddress fn selector to L1AssetHandlerHelper for diamondCut
• build: add setLayerZeroTrustedRemoteAddress fn selector to L2AssetHandlerHelper for diamondCut
• init
• refactor: expand IAssetHandler to include getLayerZeroTrustedRemoteAddress functionality
• refactor: integrate getLayerZeroTrustedRemoteAddress into L1AssetHandler
• refactor: integrate getLayerZeroTrustedRemoteAddress into L2AssetHandler
• build: add getLayerZeroTrustedRemoteAddress fn selector to L1AssetHandlerHelper for diamondCut
• build: add getLayerZeroTrustedRemoteAddress fn selector to L2AssetHandlerHelper for diamondCut
• build: initial ILayerZeroClientBaseInternalEvents test interface contract
• build: initial L1AssetHandler setLayerZeroTrustedRemoteAddress tests
• build: initial L2AssetHandler setLayerZeroTrustedRemoteAddress tests