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/PewterGym.asm

@@ -16,3 +16,23 @@ _BrockPreBattleText::
 	cont "Fine then! Show"
 	cont "me your best!"
 	done
+
+_BrockRematchPreBattleText::
+	text "You sure look"
+	line "different to"
+	cont "when we first"
+	cont "met!"
+	
+	para "The truth is..."
+	
+	para "We LEADERs have"
+	line "a right to"
+	cont "challenge the"
+	cont "champ!"
+	
+	para "Allow me to show"
+	line "you the true"
+	cont "rock-hard power"
+	cont "of my #MON!"
+	
+	done