need to update convert_polygon.py to better match areas of asc and desc orbits

[falkamelung]

Currently convert_polygon.py provides only one miaplpy.subset.lalo area. It should provide different areas for ascending and descending orbits to ensure that the same area of interest is covered by both orbits. HawaiiPuna is a good test area for this:

(I am not sure exactly the same miaplpy.subset.py option was used here. Nevertheless it is a good example)

We need to do a careful test to understand which area exactly is covered depending on the miaplpy.subset.lalo entry.