Synthetic type context

Any types created dynamically like using create typekit or converting from a different type like `enum.createFromUnion` will not have a node attached to it and so a way to provide a diagnostic target.

When creating the type however you might have some additional context that might be usefull to diagnsotics down the line. Like that type was built from value on another type and so reporting the diagnostics on the original types might be a good place.

- `enum.createFromUnion` Would make sense to report the diagnostics on the original union
- `union.createFromEnum` Would make sense to report the diagnostic on the original enum