[R&D] FITS image support from telescopes at different wavelengths

[kswang1029]

This is considered as an R&D project in order to make CARTA being able to support FITS image products from different telescopes at different wavelengths. This would be a crucial step to make CARTA capable doing multi-wavelength image visualizations. As for supporting "analytics" for non-radio cubes, that's a different scope.

The primary steps would be the following:

• collecting FITS image products from common telescopes (eg, JCMT-SCUBA2, VLT MUSE, etc)
• ensure CARTA can load those FITS images/cubes (FITS header parsing is the focus point)
• implement e2e tests to ensure images can be loaded