prep_topsApp.py #11

Add a script to prepare the inputs for topsApp.xml using option names, including:

• Download the SLC
• Download the orbits
• Download the DEM
• Write the topsApp.xml file
• Run topsApp.py --steps command
• Run geocode.py command using mintpy, as the geocoding in isce2 is not good.

The expected command:

prep_topsApp.py --ref-date --sec-date --lks-rg/x --lks-az/y --filt

With default values set for --slc-dir --orb-dir --dem-dir --unw-method