Initialize Refactor (#25981)

Shouldn't break anything, stops warning spam, logs errors qdel style at the end of the game.

Initialize now expects a hint to be returned, one of:
INITIALIZE_HINT_NORMAL - Does nothing, returned by the root proc
INITIALIZE_HINT_LATELOAD - Call atom/proc/LateInitialize
INITIALIZE_HINT_QDEL - Calls qdel on the atom

LateInitialize currently defaults to the old re-calling behavior so there should be no issues with that.
Things that didn't return a hint or fucked up somehow will be logged less loudly than they were before

No more world start warnings!

code/modules/shuttle/arrivals.dm

@@ -22,20 +22,17 @@
 	var/perma_docked = FALSE	//highlander with RESPAWN??? OH GOD!!!
 
 /obj/docking_port/mobile/arrivals/Initialize(mapload)
-	if(mapload)
-		return TRUE	//late initialize to make sure the latejoin list is populated
-
-	preferred_direction = dir
-
 	if(SSshuttle.arrivals)
 		WARNING("More than one arrivals docking_port placed on map!")
-		qdel(src)
-		return
-
+		return INITIALIZE_HINT_QDEL
 	SSshuttle.arrivals = src
 
 	. = ..()
 
+	preferred_direction = dir
+	return INITIALIZE_HINT_LATELOAD	//for latejoin list
+
+/obj/docking_port/mobile/arrivals/LateInitialize()
 	areas = list()
 
 	var/list/new_latejoin = list()