[WIP] add a python script to remove the finest level from plotfile

[zingale]

Summary

Additional background

Checklist

The proposed changes:

• [ ] fix a bug or incorrect behavior in AMReX
• [x] add new capabilities to AMReX
• [ ] changes answers in the test suite to more than roundoff level
• [ ] are likely to significantly affect the results of downstream AMReX users
• [ ] include documentation in the code and/or rst files, if appropriate

[zingale]

this works, but I want to clean it up some

[zingale]

closing this -- this was an experiment for visualization