QmlDesigner: Add id for 3d items imported from user content

Fixes: QDS-12927
Change-Id: I54537d864cdfb9748ae8e388536a57616de2d543
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/plugins/qmldesigner/components/contentlibrary/contentlibraryview.cpp

@@ -199,6 +199,8 @@ void ContentLibraryView::connectImporter()
                                                                 {"y", pos.y()},
                                                                 {"z", pos.z()}});
                         m_bundleItemTarget.defaultNodeListProperty().reparentHere(newNode);
+                        newNode.setIdWithoutRefactoring(model()->generateNewId(
+                            newNode.simplifiedTypeName(), "node"));
                         clearSelectedModelNodes();
                         selectModelNode(newNode);
                     });