Support fireman carrying people onto morgue trays and other bucklable objects (stasis beds, operating tables, chairs) (#51539)

* You can now fireman carry people onto trays

* Support putting fireman carried people to buckle

* Reverse conditions

* Only attach to bucklables if adjacent, and forcably move to the turf so you don't just drop them

code/game/objects/structures/morgue.dm

@@ -341,6 +341,17 @@ GLOBAL_LIST_EMPTY(crematoriums)
 	else
 		to_chat(user, "<span class='warning'>That's not connected to anything!</span>")
 
+/obj/structure/tray/attackby(obj/P, mob/user, params)
+	if(!istype(P, /obj/item/riding_offhand))
+		return ..()
+
+	var/obj/item/riding_offhand/riding_item = P
+	var/mob/living/carried_mob = riding_item.rider
+	if(carried_mob == user) //Piggyback user.
+		return
+	user.unbuckle_mob(carried_mob)
+	MouseDrop_T(carried_mob, user)
+
 /obj/structure/tray/MouseDrop_T(atom/movable/O as mob|obj, mob/user)
 	if(!ismovable(O) || O.anchored || !Adjacent(user) || !user.Adjacent(O) || O.loc == user)
 		return