Optimizes qdel related things (slight init time savings) (#70729)

* Moves spawners and decals to a different init/delete scheme

Rather then fully creating and then immediately deleting these things,
we instead do the bare minimum.

This is faster, if in theory more fragile. We should be safe since any
errors should be caught in compile since this is very close to a
"static" action. It does mean these atoms cannot use signals, etc.

* Potentially saves init time, mostly cleans up a silly pattern

We use sleeps and INVOKE_ASYNC to ensure that handing back turfs doesn't
block a space reservation, but this by nature consumes up to the
threshold and a bit more of whatever working block we were in.

This is silly. Should just be a subsystem, so I made it one, with
support for awaiting its finish if you want to

* Optimizes garbage/proc/Queue slightly

Queue takes about 1.6 seconds to process 26k items right now.
The MASSIVE majority of this time is spent on using \ref
This is because \ref returns a string, and that string requires being
inserted into the global cache of strings we store

What I'm doing is caching the result of ANY \ref on the datum it's
applied to. This ensures previous uses will never decay from the string
tree.

This saves about 0.2 seconds of init

code/controllers/subsystem/garbage.dm

@@ -207,7 +207,7 @@ SUBSYSTEM_DEF(garbage)
 				var/type = D.type
 				var/datum/qdel_item/I = items[type]
 
-				log_world("## TESTING: GC: -- \ref[D] | [type] was unable to be GC'd --")
+				log_world("## TESTING: GC: -- [text_ref(D)] | [type] was unable to be GC'd --")
 				#ifdef TESTING
 				for(var/c in GLOB.admins) //Using testing() here would fill the logs with ADMIN_VV garbage
 					var/client/admin = c
@@ -249,7 +249,7 @@ SUBSYSTEM_DEF(garbage)
 		HardDelete(D)
 		return
 	var/gctime = world.time
-	var/refid = "\ref[D]"
+	var/refid = text_ref(D)
 
 	D.gc_destroyed = gctime
 	var/list/queue = queues[level]
@@ -261,7 +261,7 @@ SUBSYSTEM_DEF(garbage)
 	++delslasttick
 	++totaldels
 	var/type = D.type
-	var/refID = "\ref[D]"
+	var/refID = text_ref(D)
 
 	var/tick_usage = TICK_USAGE
 	del(D)
@@ -376,7 +376,7 @@ SUBSYSTEM_DEF(garbage)
 				D.find_references() //This breaks ci. Consider it insurance against somehow pring reftracking on accident
 			if (QDEL_HINT_IFFAIL_FINDREFERENCE) //qdel will, if REFERENCE_TRACKING is enabled and the object fails to collect, display all references to this object.
 				SSgarbage.Queue(D)
-				SSgarbage.reference_find_on_fail["\ref[D]"] = TRUE
+				SSgarbage.reference_find_on_fail[text_ref(D)] = TRUE
 			#endif
 			else
 				#ifdef TESTING