Introduce `z64pause_menu.h` header

[AngheloAlf]

Make a new z64pause_menu.h header for all the public facing kaleido stuff.

All the private kaleido stuff was kept on the overlay's header (overlays/kaleido_scope/ovl_kaleido_scope/z_kaleido_scope.h). I also tried to remove all the uses of that header from code files and overlays other than kaleido itself. The only exceptions are code files that are part of the kaleido system (kaleido manager, kaleido setup and kaleido call).

I also made a few small cleanups, like introduce the PAUSE_PAGE_MAX value on the PauseMenuPage enum

[AngheloAlf]

I added the IS_PAUSED macro from OoT and changed the other macros to take a pauseCtx argument