Color and Team don't get initialised when they should be

[anarchuser]

With Kotlin, you shouldn't get unchecked NullPointerExceptions or the related IllegalArgumentException. However, sometimes, Colors and Teams aren't initialised even though they should be, resulting in exceptions that shouldn't exist.

7042b6b (#294) fails due to this.

[anarchuser]

Another artifact resulting from the same issue for Team:
https://github.com/CAU-Kiel-Tech-Inf/backend/blob/fd9c93e2ec742fbbe14ccb48522a3c921fcd3968/plugin/src/shared/sc/plugin2021/GameState.kt#L44-L49

The line commented out should suffice. However, due to this issue, the more complicated setup with the when clause is needed.

[anarchuser]

Potential reason: XStream doesn't serialise them properly