MAST: Read product function for MastMissions

[snbianco]

A function in the MastMissions class that can read products into memory.

For FITS files, we use astropy.io.fits.open. The product files are downloaded and cached by Astropy, and then read into a HDUList object.

For ASDF files, we use fsspec and asdf. Our downloads for Roman data are redirected to S3, so these files are not downloaded and are streamed directly into asdf.AsdfFile objects.

[codecov]

Codecov Report

❌ Patch coverage is 88.46154% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 73.23%. Comparing base (70dd42f) to head (7808985).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
astroquery/mast/missions.py	88.46%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3593      +/-   ##
==========================================
+ Coverage   73.21%   73.23%   +0.02%     
==========================================
  Files         226      226              
  Lines       21053    21093      +40     
==========================================
+ Hits        15414    15448      +34     
- Misses       5639     5645       +6     

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[scfleming]

Until we have a more mature version ready, can we please ensure documentation / tutorials call out that for FITS files read_product() still downloads the file locally, so people working on Roman work who may want to use this to download HST or JWST FITS files aren't surprised if read_product() is using up credits writing to local cloud storage on them?

I presume this can be avoided once there's a "get_s3_uris()" endpoint in MissionMAST for all the supported missions beyond Roman?