[MIRROR] Replaced body zone magic strings with defines (#6004)

* Replaced body zone magic strings with defines

* merge conflicts

code/modules/mob/living/carbon/death.dm

@@ -35,7 +35,7 @@
 					qdel(O) //so the brain isn't transfered to the head when the head drops.
 					continue
 				var/org_zone = check_zone(O.zone) //both groin and chest organs.
-				if(org_zone == "chest")
+				if(org_zone == BODY_ZONE_CHEST)
 					O.Remove(src)
 					O.forceMove(Tsec)
 					O.throw_at(get_edge_target_turf(src,pick(GLOB.alldirs)),rand(1,3),5)