QmlDesigner: Start requested timer when it's created in 3D view

Fixes: QDS-12659
Change-Id: I78f5854185e4efebc00ea63c5dd290dc851e21eb
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/tools/qml2puppet/qml2puppet/editor3d/generalhelper.cpp

@@ -1436,6 +1436,7 @@ void GeneralHelper::requestTimerEvent(const QString &timerId, qint64 delay)
             emit requestedTimerEvent(timerId);
         });
         m_eventTimers[timerId] = timer;
+        timer->start(delay);
     }
 }