Transfer all item shadow functions to the item class

src/Worker/CreateShadowEntry.php

@@ -8,7 +8,7 @@
 
 namespace Friendica\Worker;
 
-require_once("include/threads.php");
+use Friendica\Model\Item;
 
 class CreateShadowEntry {
 	public static function execute($message_id = 0) {
@@ -16,6 +16,6 @@ class CreateShadowEntry {
 			return;
 		}
 
-		add_shadow_entry($message_id);
+		Item::addShadowPost($message_id);
 	}
 }

src/Worker/ThreadUpdate.php

@@ -1,11 +0,0 @@
-<?php
-namespace Friendica\Worker;
-
-require_once("include/threads.php");
-
-class ThreadUpdate {
-	public static function execute() {
-		update_threads();
-		update_threads_mention();
-	}
-}