SSoverlay improvements and tweaks (#32371)

* Overlay per-type cost logging.

Overlays will now log how long each type took to process.

Changed up how overlays was done to account for the fact its a queue and not a processor. (it was using almost none of the processing subsystem framework)

Made the overlay loop faster by making it not cut the list until the end.

Added a simple generic benchmark stat tracking system.

I don't know how much overhead this adds to overlays. i may put it behind testing or something, but i do want to test this on the serbers to get some stats.

* Removes flush() as it was creating race conditions

* Use ref

* text2file

* Atoms added as an overlay will have their pending overlays compiled before being converted to an appearance

code/game/atoms.dm

@@ -99,7 +99,6 @@
 
 	LAZYCLEARLIST(overlays)
 	LAZYCLEARLIST(priority_overlays)
-	//SSoverlays.processing -= src	//we COULD do this, but it's better to just let it fall out of the processing queue
 
 	QDEL_NULL(light)
 

code/game/world.dm

@@ -124,7 +124,7 @@ GLOBAL_PROTECT(security_mode)
 		if(I in input)
 			handler = topic_handlers[I]
 			break
-	
+
 	if((!handler || initial(handler.log)) && config && CONFIG_GET(flag/log_world_topic))
 		WRITE_FILE(GLOB.world_game_log, "TOPIC: \"[T]\", from:[addr], master:[master], key:[key]")