Casting VAR_ID string

Author: fogelito

src/Database/Database.php

@@ -6518,6 +6518,9 @@ public function casting(Document $collection, Document $document): Document
                         if ($this->adapter->getIdAttributeType() === Database::VAR_ID_INT) {
                             $node = (int)$node;
                         }
+                        else {
+                            $node = (string)$node;
+                        }
                         break;
                     case self::VAR_INTEGER:
                         $node = (int)$node;