Update to v0.3.2

[gshiroma]

Changes:

• Add script plant_isce3_rtc.
• Replace decimation algorithm for mask layers from averaging (multilooking) to median.
• Adds default processing frequency (first available) to plant_isce3_filter.
• Add option to plant_isce3_util to save NISAR product footprint in the HTML format (option --footprint-html).
• Remove all test data before new execution.
• Improve plant_isce3_batch_processing.
• Fix bugs and lint code.