Refactors do_after w/ TG's do_after (#18282)

* part1

* keeps range ability

* no cog vore

code/modules/lootpanel/contents.dm

@@ -1,6 +1,6 @@
 /// Adds the item to contents and to_image (if needed)
 /datum/lootpanel/proc/add_to_index(datum/search_object/index)
-	RegisterSignal(index, COMSIG_PARENT_QDELETING, PROC_REF(on_searchable_deleted))
+	RegisterSignal(index, COMSIG_QDELETING, PROC_REF(on_searchable_deleted))
 	if(isnull(index.icon))
 		to_image += index
 
@@ -50,5 +50,5 @@
 		if(QDELETED(index))
 			continue
 
-		UnregisterSignal(index, COMSIG_PARENT_QDELETING)
+		UnregisterSignal(index, COMSIG_QDELETING)
 		qdel(index)

code/modules/lootpanel/search_object.dm

@@ -32,7 +32,7 @@
 		RegisterSignals(item, list(
 			COMSIG_ITEM_PICKUP,
 			COMSIG_MOVABLE_MOVED,
-			COMSIG_PARENT_QDELETING,
+			COMSIG_QDELETING,
 			), PROC_REF(on_item_moved))
 
 	// Icon generation conditions //////////////