Adds ChessPiece's species hardsuit sprites

Adds ChessPiece's onmob and inventory sprites for unathi and skrell hardsuits, as well as nicer tajaran hardsuit inventory sprites to replace the current placeholder ones. Adds hardsuit spritesheet entries for unathi (skrell will come later).

(cherry picked from commit cd661d92804233623dd67b6aff8d755364907bc3)

Conflicts:
	code/modules/clothing/spacesuits/rig.dm
Allows refitting to change worn sprite

(cherry picked from commit 30464da6ef8bc58bc3a8b188895ccfaa86e258bf)

Conflicts:
	code/modules/clothing/clothing.dm
	code/modules/clothing/spacesuits/rig.dm