SkyFit2 able to read bz2 files directly

[g7gpr]

Allows SkyFit2 to read in bz2 files and write a xx0001.cal file in the working directory.

(vRMS) david@lap-deb-01:~/source/RMS$ python -m Utils.SkyFit2 ~/RMS_data/ArchivedFiles/AU000K_20250624_100321_533326_detected.tar.bz2

Platepar written to: /tmp/tmpuz3mdypw/platepar_cmn2010.cal
Writing modified platepar to /home/david/source/RMS/au000k.cal

This saves manually decompressing the directories. Uses the tempfile library and context handlers to clean up afterwards.