Properly include moshi with generated adapters

[rmeissner]

To avoid issues as in #14 (partial fix with #15) we should use proper objects with moshi and generate adapters. These adapters will skip unknown values and known values are properly type checked.

ToDos

• Add moshi code generation
• Create data class for web socket message to bridge
• Check current parsing logic and potentially create more data classes
• Create a json parser interface and abstract away moshi in all classes to allow replacement by other json parsers