Convert preferences to /tg/ preferences (#16449)

* Convert all preferences to /tg/ preferences

* Move obfuscate key/job to game options

* Add abstract_type to each of the new subtypes

* Convert ignored players to tg prefs

* Yet another global category list removed

* Fix error, convert client FPS

* Convert UI_style, UI_alpha, and UI_color to tg prefs

* Clean up a little, convert tooltipstyle

* Convert ambience to tg prefs

* Remove chat_timestamp, tgchat can do this internally and gives localized results

* Convert admin ooc color to pref, merk 01_ui.dm

* Convert uplinklocation to a tg pref

* Fixup byond:// links

* Convert name_is_always_random

* Convert spawnpoint

* v16 savefile migration in prep for converting 03_body.dm

* Convert all colors to tg prefs

* Finish converting ooc notes

code/modules/asset_cache/assets/preferences.dm

@@ -1,3 +1,44 @@
+/// Assets generated from `/datum/preference` icons
+/datum/asset/spritesheet/preferences
+	name = "preferences"
+	early = TRUE
+
+/datum/asset/spritesheet/preferences/create_spritesheets()
+	var/list/to_insert = list()
+
+	for(var/preference_key in GLOB.preference_entries_by_key)
+		var/datum/preference/choiced/preference = GLOB.preference_entries_by_key[preference_key]
+		if(!istype(preference))
+			continue
+
+		if(!preference.should_generate_icons)
+			continue
+
+		for(var/preference_value in preference.get_choices())
+			var/create_icon_of = preference.icon_for(preference_value)
+
+			var/icon/icon
+			var/icon_state
+
+			if(ispath(create_icon_of, /atom))
+				var/atom/atom_icon_source = create_icon_of
+				icon = initial(atom_icon_source.icon)
+				icon_state = initial(atom_icon_source.icon_state)
+			else if(isicon(create_icon_of))
+				icon = create_icon_of
+			else
+				CRASH("[create_icon_of] is an invalid preference value (from [preference_key]:[preference_value]).")
+
+			to_insert[preference.get_spritesheet_key(preference.pref_serialize(preference_value))] = list(icon, icon_state)
+
+	for(var/spritesheet_key in to_insert)
+		var/list/inserting = to_insert[spritesheet_key]
+		Insert(spritesheet_key, inserting[1], inserting[2])
+
+/// Returns the key that will be used in the spritesheet for a given value.
+/datum/preference/proc/get_spritesheet_key(value)
+	return "[savefile_key]___[sanitize_css_class_name(value)]"
+
 /// Sends information needed for shared details on individual preferences
 /datum/asset/json/preferences
 	name = "preferences"