Add retriever to CloudObject and allow retrieval of related objects

CloudObjects/SDK/ObjectRetriever.php

@@ -196,7 +196,8 @@ class ObjectRetriever implements CustomCacheAndLogInterface {
 			return null;
 		}
 
-		$object = new CloudObject($coid, $node);
+		$object = (new CloudObject($coid, $node))
+			->setObjectRetriever($this);
 
 		if ($this->defaultReader) {
 			// Initialize CloudObject with default reader if it is set