Revamp Pokemon Mansion B2F

This was hell to do. There is still one bug in there, and that's the item pickups don't work for some reason. I don't know how these work honestly so if anyone wants to sort that go ahead.

Anyway, some stuff on the map;
- Currently, a warp from B1F leads there, which is intentionally non-returnable. The player walks through the whole map to get to the warp panel. A walk of humanity's shame, if you will. A warp for where the player is meant to go will be necessary later.
- Lore from Japanese media, particularly the first movie's interpretation of Mewtwo, is included. This is based on context clues on its canonicity from LGPE and other bits.
- A clue on how to get the Old Sea Chart is not-so-subtly included.

The MissingNo. event is unfinished, I intend for Martha to deal with that. The text intentionally lacks a "done" bit to force an unpredictable error; I believe this is inconsequential gameplay-wise and should make for a good opening quote when fighting it.

Oh, and Faraway Island has Mankey, Butterfree, and Primeape as find-able Pokemon now. This should be expanded upon later.

data/maps/songs.asm

@@ -116,7 +116,7 @@ MapSongBanks::
 	db MUSIC_INDIGO_PLATEAU, BANK(Music_IndigoPlateau) ; LANCES_ROOM
 	db MUSIC_DUNGEON2, BANK(Music_Dungeon2) ; UNUSED_MAP_72 / FARAWAY ISLAND INSIDE
 	db MUSIC_DUNGEON2, BANK(Music_Dungeon2) ; UNUSED_MAP_73 / FARAWAY ISLAND OUTSIDE 
-	db MUSIC_SS_ANNE, BANK(Music_SSAnne) ; UNUSED_MAP_74
+	db MUSIC_CINNABAR_MANSION, BANK(Music_CinnabarMansion) ; UNUSED_MAP_74 / POKEMON MANSION B2F
 	db MUSIC_SS_ANNE, BANK(Music_SSAnne) ; UNUSED_MAP_75
 	db MUSIC_PALLET_TOWN, BANK(Music_PalletTown) ; HALL_OF_FAME
 	db MUSIC_ROUTES1, BANK(Music_Routes1) ; UNDERGROUND_PATH_NORTH_SOUTH