feat(item): added client shortcut function

Author: DIOHz0r

src/Glpi/Api/Rest/ItemHandler.php

@@ -40,6 +40,13 @@ public function __construct(Client $client) {
       $this->client = $client;
    }
 
+   /**
+    * @return Client
+    */
+   public function getClient() {
+      return $this->client;
+   }
+
    /**
     * Return the instance fields of itemtype identified by id.
     * @param string $itemType