Gym Leader Rematches!

This commit adds a large fundamental change to KEP, that being Gym Rematches.

This is achieved alongside a rework to the script that makes those post-game-gating NPCs shift around. If you add a new one, just add its constant to the lists you'll see in the Hall of Fame script.

It also fixes a few bugs:
- Fixed a bug where Cinnabar Gym loaded a fleet of Blaines. This occurred due to the way he is coded at base, and a misunderstanding I had when implementing his scaling. This is now fixed by standardising his gym script instead, while letting the gym trainers still use the old one.
- Fixed a bug where the Up-Grade NPC would not appear after beating Silph Co. 11F. However, Giovanni currently seems to have trouble with his text. This floor needs some re-coding anyway, given we need to add Jessie and James to it.

And some misc. changes:
- Changed the first Moon Stone in Mt. Moon to a Poison Stone for the Nidoking speedrunners
- Debug Mode now has a line of code to set up the post-game easily
- Changed Surge's initial battle text to Yellow's
- Added Sabrina's more accurate LGPE initial battle text, referring to the spoon she bent by accident

data/maps/objects/SaffronGym.asm

@@ -1,6 +1,10 @@
 SaffronGym_Object:
 	db $2e ; border block
 
+; I tried to add a way to instantly get to the start.
+; But...it breaks the *entire* puzzle for some reason.
+; Yes, I tried changing the one in Sabrina's room. No, it didn't accomplish anything.
+
 	def_warp_events
 	warp_event  8, 17, LAST_MAP, 3
 	warp_event  9, 17, LAST_MAP, 3
@@ -34,6 +38,7 @@ SaffronGym_Object:
 	warp_event 19, 15, SAFFRON_GYM, 26
 	warp_event 15, 17, SAFFRON_GYM, 12
 	warp_event 19, 17, SAFFRON_GYM, 20
+	;warp_event 10,  8, SAFFRON_GYM, 20 ; New warp directly to the start of the gym, like later games.
 
 	def_bg_events