Port DmIcon & Image components from TG (#26623)

* Port DmIcon & Image components from TG

* Documentation

* Uh oh

* I hate it

* I will bang you

code/controllers/subsystem/non_firing/SSassets.dm

@@ -36,4 +36,4 @@ SUBSYSTEM_DEF(assets)
 		if(initial(asset_to_load._abstract))
 			continue
 
-		get_asset_datum(type)
+		load_asset_datum(type)

code/controllers/subsystem/non_firing/SSearly_assets.dm

@@ -0,0 +1,18 @@
+/// Initializes any assets that need to be loaded ASAP.
+SUBSYSTEM_DEF(early_assets)
+	name = "Early Assets"
+	init_order = INIT_ORDER_EARLY_ASSETS
+	flags = SS_NO_FIRE
+
+/datum/controller/subsystem/early_assets/Initialize()
+	for(var/datum/asset/asset_type as anything in subtypesof(/datum/asset))
+		if(asset_type::_abstract == asset_type)
+			continue
+
+		if(!asset_type::early)
+			continue
+
+		if(!load_asset_datum(asset_type))
+			stack_trace("Could not initialize early asset [asset_type]!")
+
+		CHECK_TICK