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`.
This allows all controllers to navigate the UI, which enhances
compatibility with PC handhelds when external controllers are connected.
Previously, only the first device was allowed to use `ui_*` actions
out of the box, which means that on a PC handheld, external controllers
couldn't navigate the UI (since the first ID is always the built-in controller).
Marco Zepeda
Goldenlion5648
Rémi Verschelde
Thaddeus Crews
Nintorch
AR
Michael Alexsander
Hugo Locurcio
A Thousand Ships