Pikachu/Eevee Mode

So some bits of this are untested, but the base starters are unaffected. I had to work a lot with the sprite limits so Oak's lab has been changed a bit.

This adds a Pikachu and Eevee "mode" to the game, allowing you to pick them as starters. When doing so, the Rival will always pick the opposite.

There are some glitches;
- Picking Charmander makes Blue erase himself from existence
- Picking from anywhere other than the front of the table may have odd results.
- Oak has to be shown in the lab at the start from now on for some reason; side effect of removing the dexes, there's definitely a fix for this.
These are from me not finishing the ball picking process - it was a little weird.

Parties based on starters have been updated but I had to cut out a lot of unused trainer slots.

Also the unused names were removed.

constants/map_constants.asm

@@ -59,7 +59,7 @@ DEF FIRST_INDOOR_MAP EQU const_value
 	mapconst REDS_HOUSE_1F,                  4,  4 ; $25
 	mapconst REDS_HOUSE_2F,                  4,  4 ; $26
 	mapconst BLUES_HOUSE,                    4,  4 ; $27
-	mapconst OAKS_LAB,                       6,  5 ; $28
+	mapconst OAKS_LAB,                       6,  7 ; $28
 	mapconst VIRIDIAN_POKECENTER,            4,  7 ; $29
 	mapconst VIRIDIAN_MART,                  4,  4 ; $2A
 	mapconst VIRIDIAN_SCHOOL_HOUSE,          4,  4 ; $2B