- AR enabled measurements
- UI improvements

- The image button has now a round cornered background

- due to the usage of fragment navigation in onResume a separate navigation request onRequestPermissionResult leads to two  same navigation requests. The second navigation request causes then a NPE, because the necessary view is not existent anymore

- now, the common question layout components, such as title and info button, are put into an extra layout file
- this file is included by the various question layout files

- before, the app got stuck in the intro fragment when the screen was turned off. The reason is that the timer to fire the next fragment transition is not triggered in background.
- fix this by starting the timer in onResume()

- move to own package
- use now HOT OSM tile provider
- implement quit dialog and show it when pressing on back

- now the measurement is return to the question fragment
- only use decimals without subcentimeter resolution for measure results

.. to level 21

... to also support non-ARCore devices

... and measurement questions