Merge branch 'feature/messenger-receive-file' into 'development'

Docs/XXMessengerClient.md

...ssenger.xcworkspace/xcshareddata/swiftpm/Package.resolved

Sources/XXClient/Callbacks/ReceiveFileCallback.swift

...ngerClient/Messenger/Functions/MessengerReceiveFile.swift

...nger/Functions/MessengerRegisterReceiveFileCallback.swift

...ssengerClient/Messenger/Functions/MessengerSendFile.swift

...ient/Messenger/Functions/MessengerStartFileTransfer.swift

Sources/XXMessengerClient/Messenger/Messenger.swift

...es/XXMessengerClient/Messenger/MessengerEnvironment.swift

...XMessengerClient/Utils/ReceiveFileCallbacksRegistry.swift

...Tests/Messenger/Functions/MessengerReceiveFileTests.swift

...Functions/MessengerRegisterReceiveFileCallbackTests.swift

...entTests/Messenger/Functions/MessengerSendFileTests.swift

...Messenger/Functions/MessengerStartFileTransferTests.swift

Tests/XXMessengerClientTests/TestHelpers/TestDoubles.swift

...ClientTests/Utils/ReceiveFileCallbacksRegistryTests.swift