Archery Tweaks (#8670)

* Add proper custom arrows. (cross)Bows "render" proper arrows over themselves in inventory and on ground. Hardlight bow no longer deletes other arrows on removal.

* Fix subtyping issue.
Add Chitin arrow type.

* Remember to hit save, kids.

* Fixfix. Add true Unga arrow utilizing the Ancient Art of Sharp Rocks.

code/modules/materials/sheets/_sheets.dm

@@ -1,6 +1,7 @@
 // Stacked resources. They use a material datum for a lot of inherited values.
 // If you're adding something here, make sure to add it to fifty_spawner_mats.dm as well
 /obj/item/stack/material
+	name = "material sheet"
 	force = 5.0
 	throwforce = 5
 	w_class = ITEMSIZE_NORMAL
@@ -86,4 +87,4 @@
 	else if(istype(W, /obj/item/stack/rods))
 		material.build_rod_product(user, W, src)
 		return
-	return ..()
+	return ..()