Rogue stickyban detection system. (#19201)

* Rogue stickyban detection system.

This will detect when stickybans go rogue and revert them to whatever their state was when the world started.

* does the remie

* Increases STICKYBAN_MAX_MATCHES to 20 to prevent gaming

code/controllers/subsystem/stickyban.dm

@@ -0,0 +1,36 @@
+var/datum/subsystem/stickyban/SSstickyban
+
+/datum/subsystem/stickyban
+	name = "Sticky Ban"
+	init_order = -10
+	flags = SS_NO_FIRE
+
+	var/list/cache = list()
+
+/datum/subsystem/stickyban/New()
+	NEW_SS_GLOBAL(SSstickyban)
+
+/datum/subsystem/stickyban/Initialize(timeofday)
+	var/list/bannedkeys = world.GetConfig("ban")
+	//sanitize the sticky ban list
+	for (var/bannedkey in bannedkeys)
+		var/ckey = ckey(bannedkey)
+		var/list/ban = stickyban2list(world.GetConfig("ban", bannedkey))
+
+		//byond stores sticky bans by key, that can end up confusing things
+		//i also remove it here so that if any stickybans cause a runtime, they just stop existing
+		world.SetConfig("ban", bannedkey, null)
+
+		if (!ban["ckey"])
+			ban["ckey"] = ckey
+
+		//storing these can break things and isn't needed for sticky ban tracking
+		ban -= "IP"
+		ban -= "computer_id"
+
+		world.SetConfig("ban", ckey, list2stickyban(ban))
+
+		ban["matches_this_round"] = list()
+		ban["existing_user_matches_this_round"] = list()
+		ban["admin_matches_this_round"] = list()
+		cache[ckey] = ban