callable_method_pointer.h
callable_mp.h
This allows removing it from `class_db.h`, significantly reducing the amount of files that include it transitively. Also includes some include cleanup in `control.h` and `rich_text_label.h` done while ensure they don't depend on `callable_mp`.
Co-authored-by: Adam Scott <ascott.ca@gmail.com> Co-authored-by: A Thousand Ships <96648715+AThousandShips@users.noreply.github.com>