[MIRROR] Convert preferences to /tg/ preferences (#9797)

Co-authored-by: ShadowLarkens <shadowlarkens@gmail.com>
Co-authored-by: Kashargul <144968721+Kashargul@users.noreply.github.com>

code/_helpers/_lists.dm

@@ -974,6 +974,13 @@ var/global/list/json_cache = list()
 			new_value = deep_copy_list_alt(value)
 		copied_list[key_or_value] = new_value
 
+/// Turns an associative list into a flat list of keys
+/proc/assoc_to_keys(list/input)
+	var/list/keys = list()
+	for(var/key in input)
+		UNTYPED_LIST_ADD(keys, key)
+	return keys
+
 //CHOMPAdd start
 /proc/pick_weight(list/list_to_pick)
 	var/total = 0