Moves languages to a holder datum, gives mind its own language holder

code/_onclick/hud/screen_objects.dm

@@ -91,10 +91,9 @@
 	screen_loc = ui_language_menu
 
 /obj/screen/language_menu/Click()
-	var/mob/living/L = usr
-	if(!istype(L))
-		return
-	L.open_language_menu(usr)
+	var/mob/M = usr
+	var/datum/language_holder/H = M.get_language_holder()
+	H.open_language_menu(usr)
 
 /obj/screen/inventory
 	var/slot_id	// The indentifier for the slot. It has nothing to do with ID cards.