Quirk preferences fixes (#44823)

Removes the useless split by value lists. Updates savefile after
removing invalid quirks. I'd prefer usual savefile validation but quirk
lists are built pretty late. Other solution would be hooking all prefs
to after quirk SS initializes, this seems less intrusive if ugly but
I'm open to alternative suggestions.

code/controllers/subsystem/processing/quirks.dm

@@ -30,9 +30,14 @@ PROCESSING_SUBSYSTEM_DEF(quirks)
 		quirk_points[initial(T.name)] = initial(T.value)
 
 /datum/controller/subsystem/processing/quirks/proc/AssignQuirks(mob/living/user, client/cli, spawn_effects)
+	var/badquirk = FALSE
 	for(var/V in cli.prefs.all_quirks)
 		var/datum/quirk/Q = quirks[V]
 		if(Q)
 			user.add_quirk(Q, spawn_effects)
 		else
 			stack_trace("Invalid quirk \"[V]\" in client [cli.ckey] preferences")
+			cli.prefs.all_quirks -= V
+			badquirk = TRUE
+	if(badquirk)
+		cli.prefs.save_character()