Add Powder Snow, fix Moltres

- Adds Powder Snow; GSC stats, was cut from RBY.
- Articuno, Jynx, Buu, Glaceon, Alolan Sandslash, and Alolan Ninetales get Powder Snow at L1.
- Glaceon also gets Powder Snow over Aurora Beam at L1; a nerf that makes it more accurate to its PLA learnset. Glaceon doesn't normally get this move.
- Moltres now gets Flamethrower at L51, fixing an error that GSC fixed. Leer is off by exactly 10 spaces. Leer has been made an L1 move, making it consistent with Articuno's Powder Snow. Does not affect legality, given the Tradeback Tutor.
- Because I'm pedantic, Zapdos gets Thunderbolt as an L1 move like Articuno's Ice Beam, so they all stay the same. Does not affect legality.

engine/debug/debug_menu.asm

@@ -108,9 +108,9 @@ TestBattle:
 	ld [hl], a
 
 	; Player's Pokemon.
-	ld a, MANKEY
+	ld a, GLACEON
 	ld [wcf91], a
-	ld a, 10
+	ld a, 16
 	ld [wCurEnemyLVL], a
 	xor a
 	ld [wMonDataLocation], a
@@ -122,7 +122,7 @@ TestBattle:
 	ld hl, wPartyMon1Moves
 	ld a, UPPERCUT ; Something super weak
 	ld [hli], a
-	ld a, KARATE_CHOP ; Test new failure text
+	ld a, POWDER_SNOW ; Test new failure text
 	ld [hli], a
 	ld a, LOW_KICK ; Something that'll miss easily
 	ld [hli], a
@@ -130,7 +130,7 @@ TestBattle:
 	ld [hli], a
 	
 	; Opponent's Pokemon.
-	ld a, MANKEY ; Test new theme
+	ld a, BUU ; Test new theme
 	ld [wCurOpponent], a
 	ld a, 10 ; Set the level you want here.
 	ld [wCurEnemyLVL], a