Patch treatment of different NISAR modes

[sssangha]

Introducing flexibility to specify specific bandwidth mode for NISAR GUNWs with the --bandwidth option for ariaDownload, ariaPlot, ariaExtract, and ariaTSsetup. E.g.:

(ARIA-tools_dev) [ssangha@trappist D060]$ ariaDownload.py --mission NISAR -d d -b '50.54966 54.57992 155.79270 160.78594' -t 60 -o Url --bandwidth 4000
*****************************************************************
2026-04-16 15:03:49,878 - ariaDownload.py - INFO - *** Download Function ***
*****************************************************************
2026-04-16 15:03:52,772 - ARIAtools.util.misc - INFO - Filtered out 2 products not matching bandwidth '4000'.
2026-04-16 15:03:52,784 - ariaDownload.py - INFO - Wrote -- 12 -- product urls to: /u/duvel-d2/ssangha/NISAR_work/gareth/des/D060/products/track60_bbox155W50S161E55N_0.txt

The program also catches and prints a clear WARNING + summary if there is a mix of different modes, before proceeding with the jobs in the case the user wishes to proceed with the limited acquisitions:

(ARIA-tools_dev) [ssangha@trappist D060]$ ariaDownload.py --mission NISAR -d d -b '50.54966 54.57992 155.79270 160.78594' -t 60 -o Url
*****************************************************************
2026-04-16 15:02:14,742 - ariaDownload.py - INFO - *** Download Function ***
*****************************************************************
2026-04-16 15:02:18,909 - ARIAtools.util.misc - WARNING - **********************************************************************
2026-04-16 15:02:18,910 - ARIAtools.util.misc - WARNING - WARNING: Heterogeneous NISAR bandwidth modes detected!
2026-04-16 15:02:18,910 - ARIAtools.util.misc - WARNING - Mixing bandwidths can introduce severe resolution and phase discontinuities.
2026-04-16 15:02:18,910 - ARIAtools.util.misc - WARNING - Breakdown of bandwidths found:
2026-04-16 15:02:18,910 - ARIAtools.util.misc - WARNING -  - Mode 2000: 2 file(s) (14.3%)
2026-04-16 15:02:18,910 - ARIAtools.util.misc - WARNING -  - Mode 4000: 12 file(s) (85.7%)
2026-04-16 15:02:18,910 - ARIAtools.util.misc - WARNING - **********************************************************************
2026-04-16 15:02:18,933 - ariaDownload.py - INFO - Wrote -- 14 -- product urls to: /u/duvel-d2/ssangha/NISAR_work/gareth/des/D060/products/track60_bbox155W50S161E55N_0.txt