Save profiling data in session

1. Open a session.
2. Record some data with the QML Profiler.
3. Switch to another session.
   The QML Profiler still shows the same data.
4. Clear the data.
5. Switch back to the first session.
   The profiling data does not come back.

It might be better if the QML Profiler data would be cleared when switching to a different session and restored when opening the session again.

As long as this does not happen, the user can explicitly save the recorded data as a workaround.