Support for GetComponent<T> variants on Unity component types
All changes from commit dae3ffd
- Add support for GetComponent<T>(), GetComponents<T>(), GetComponentInChildren<T>(), etc. This does not yet support doing GetComponent<UdonBehaviour> or getting components of user defined types
- Fix enum type propagation causing errors sometimes depending on how an enum is referenced
- Completely fix error line numbers being offset by field initializer bodies