MatrixRTC: Add combined `toDeviceAndRoomKeyTransport` (#4792)
* Add to-device and room transport
* Lint
* add doc string
* hook up automatic toDeviceKeyTransport -> roomKeyTransport switching
* lint, rename, imports
* fix logging
* fix test logger
* use mockLogger better in tests
* improve logging and reduce `EnabledTransportsChanged` emission.
* fix this binding
* lint
* simplify `onTransportChanged` callback
* refactor to construct the transports outside the RoomAndToDeviceKeyTransport
* update tests to use new RoomAndToDeiviceTransport constructor
* add depractaion comments