[MIRROR] moves runechat to a subsystem (#10167)

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

code/controllers/subsystems/runechat.dm

@@ -0,0 +1,14 @@
+TIMER_SUBSYSTEM_DEF(runechat)
+	name = "Runechat"
+	priority = FIRE_PRIORITY_RUNECHAT
+
+	var/list/datum/callback/message_queue = list()
+
+/datum/controller/subsystem/timer/runechat/fire(resumed)
+	. = ..() //poggers
+	while(message_queue.len)
+		var/datum/callback/queued_message = message_queue[message_queue.len]
+		queued_message.Invoke()
+		message_queue.len--
+		if(MC_TICK_CHECK)
+			return