Exosuit Nuclear Power Cores (#18268)

* Added power cores, a type of large battery cell that get used by
exosuits. The nuclear and phoron variants are self-charging.
* Combat mechs now start with nuclear power cores, allowing them to
sustain themselves indefinitely, so long as they stay out of the action
for a bit.
* Removed basic power cells from the mechfab, replaced with the mech
powercores.
* Mech cell statuses now instantly update as soon as the cell charges or
discharges.
* Added a stack of 10 uranium to the machinist's workshop, which can
print two nuclear power cores.

code/game/objects/items/devices/suit_cooling.dm

@@ -166,6 +166,9 @@
 			if(cell)
 				to_chat(user, SPAN_WARNING("There is \a [cell] already installed here."))
 			else
+				if(attacking_item.w_class != ITEMSIZE_NORMAL)
+					to_chat(user, SPAN_WARNING("\The [attacking_item] is too [attacking_item.w_class < ITEMSIZE_NORMAL ? "small" : "large"] to fit here."))
+					return
 				user.drop_from_inventory(attacking_item,src)
 				cell = attacking_item
 				to_chat(user, SPAN_NOTICE("You insert \the [cell]."))