StateFlow<Enum> is missing __Enum translation

[wkornewald]

For generics SKIE uses the Kotlin __Enum version as described here: https://skie.touchlab.co/features/enums#using-enums-in-generics

However, for StateFlow this generics conversion is missing. This makes it impossible to instantiate a StateFlow from iOS which contains such an enum. At least in our project we provide a KMP API for instantiating a StateFlow and that uses generics and thus only works with the __Enum version (unless you create many enum-specific functions, but that makes no sense).

One alternative would be to allow instantiating SkieSwiftStateFlow etc. from within Swift and passing an initial value as discussed here: #144 and #54