/tg/ pref datums (part 1) (#16219)

* TG Prefs (Step 1: JSON savefiles)

* TG Prefs (Step 2: Preference Datum Code)

* TG Prefs (Step 3: Convert /datum/client_preferences)

* TG Prefs (Step 4: Clean up and finishing touches)

* Fix some weird compile errors from the rebase

code/datums/progressbar.dm

@@ -41,7 +41,7 @@
 
 	progress = CLAMP(progress, 0, goal)
 	bar.icon_state = "prog_bar_[round(((progress / goal) * 100), 5)]"
-	if(!shown && user.is_preference_enabled(/datum/client_preference/show_progress_bar))
+	if(!shown && user.client?.prefs?.read_preference(/datum/preference/toggle/show_progress_bar))
 		user.client.images += bar
 		shown = 1
 
@@ -66,4 +66,4 @@
 		qdel(bar)
 	. = ..()
 
-#undef PROGRESSBAR_HEIGHT
+#undef PROGRESSBAR_HEIGHT