Consistently format WRAM values

[Rangi42]

macros/wram.asm uses db for one-byte values (like box_struct Species) and dw for two-byte values (like box_struct HPExp), leaving ds for larger values (like ds 3 for box_struct Exp) and free space. Meanwhile, wram.asm never uses dw and only uses db for wWaterRate and wWaterMons.

It could also use more UNIONs for overlapping values (like $60-byte wMonPartySpritesSavedOAM, $40-byte wTrainerCardBlkPacket, and many subsequent single bytes).

[Rangi42]

Things that should be UNIONs:

; number of hits by enemy in attacks like Double Slap, etc.
wEnemyNumHits:: ; db
; the amount of damage accumulated by the enemy while biding
wEnemyBideAccumulatedDamage:: dw

wSerialPlayerDataBlock:: ; ds $1a8

wSerialEnemyDataBlock:: ; ds $1a8

Edit: Actually wSerialPlayerDataBlock and wSerialEnemyDataBlock would span multiple sections, so they can stay as-is.