Audits wash/cleaning signals + refactors wash() to ensure no needless mob updates occur (#91259)

## About The Pull Request

This has the potential to create a lot of needless mob updates which is
not great. Now should only update a mob's clothing if it was actually
washed.

This PR

1) ensures that all wash() procs return a bitflag.
2) ensures that `wash()` proccalls which result in expensive operations
like icon updates only do so when it is necessary

## Why It's Good For The Game

Updating mob sprites is expensive, and doing it when nothing has been
changed is bad.

## Changelog

Nothing really player facing

code/game/objects/structures/window.dm

@@ -375,13 +375,17 @@
 	. = ..()
 	if(!(clean_types & CLEAN_SCRUB))
 		return
-	set_opacity(initial(opacity))
-	remove_atom_colour(WASHABLE_COLOUR_PRIORITY)
+	var/initial_opacity = initial(opacity)
+	if(opacity != initial_opacity)
+		set_opacity(initial_opacity)
+		. |= COMPONENT_CLEANED|COMPONENT_CLEANED_GAIN_XP
 	for(var/atom/movable/cleanables as anything in src)
 		if(cleanables == src)
 			continue
-		if(!cleanables.wash(clean_types))
+		var/cleanable_washed = cleanables.wash(clean_types)
+		if(!cleanable_washed)
 			continue
+		. |= cleanable_washed
 		vis_contents -= cleanables
 
 /obj/structure/window/Destroy()