Move PlayState to a new z64play.h (#1966)

* ActorContext

* frameadvance

* SfxSource

* GameOverContext

* RoomContext

* TransitionActorContext

* fix bss

* Move PlayState

* Move play functions to new header

* SAC_ENABLE

* no longer needed

* SAC_ENABLE again

* z_demo being silly

* comment

* format headers

* fix retail bss

* actually fix bss

* Cutscene_ProcessScript comment

* bss again

* Update src/code/z_demo.c

Co-authored-by: cadmic <cadmic24@gmail.com>

* rename to frame_advance and remove it from z64.h

* move macros too

* review

* Rename SequenceContext to SceneSequences

---------

Co-authored-by: cadmic <cadmic24@gmail.com>

src/code/z_effect.c

@@ -1,5 +1,7 @@
 #include "global.h"
 
+#include "z64frame_advance.h"
+
 EffectContext sEffectContext;
 
 EffectInfo sEffectInfoTable[] = {