provide a separate default style for import of V2-scores (in preferences / score)

I propose to provide a separate default style in the settings that allows to define, in what way settings that were not present in MuseScore V2 are set when they are imported in the actual version.
This should imply:
- activation of chord playback
- automatic placement
- conversion to V3 score (of the file)

The list might be longer - I have no real overview about all the new settings. But it might help to provide a better way to handle the new features.
In my special case: I have a lot of scores with piano track and additional chord symbols (either in piano or another track). Now I need to disable the chord playback for each "old" file.