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

text/CeladonGym.asm

@@ -215,3 +215,34 @@ _CeladonGymAfterBattleText8::
 	para "Wait 'til next"
 	line "time!"
 	done
+
+_ErikaRematchPreBattleText::
+	text "If it isn't the"
+	line "one filling out"
+	cont "the #DEX."
+	
+	para "I do hope things"
+	line "have been going"
+	cont "well since our"
+	cont "last encounter."
+	
+	para "...I see."
+	
+	para "You certainly"
+	line "have been busy."
+	
+	para "I'm not fond of"
+	line "those kinds of"
+	cont "public things..."
+	
+	para "But battles are"
+	line "different. That's"
+	cont "what you came"
+	cont "for, isn't it?"
+	done
+
+_ErikaRematchDefeatedText::
+	text "Oh! It"
+	line "appears it is"
+	cont "my loss..."
+	prompt