Add PLATO to Catalogs

[jaymedina]

Functionality: Following the latest MAST patch, this PR adds PLATO as a query option to astroquery.mast.Catalogs.query_region and query_object.

Documentation: mast.rst is updated to reflect new PLATO DR1 availability.

Testing: test_mast_remote.py is updated with a regression test for PLATO query.

[codecov]

Codecov Report

Merging #2279 (5e7358f) into main (5740dc7) will decrease coverage by 0.00%.
The diff coverage is 33.33%.

❗ Current head 5e7358f differs from pull request most recent head 03eca88. Consider uploading reports for the commit 03eca88 to get more accurate results

@@            Coverage Diff             @@
##             main    #2279      +/-   ##
==========================================
- Coverage   62.74%   62.73%   -0.01%     
==========================================
  Files         130      130              
  Lines       16837    16840       +3     
==========================================
+ Hits        10564    10565       +1     
- Misses       6273     6275       +2     

Impacted Files	Coverage Δ
astroquery/mast/collections.py	90.25% <33.33%> (-1.85%)	⬇️
astroquery/mast/cloud.py	22.66% <0.00%> (+0.58%)	⬆️

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[pep8speaks]

Hello @jaymedina! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2022-02-18 16:27:33 UTC

[bsipocz]

Minor comments only. Please squash commits though.

[bsipocz]

Thanks @jaymedina!

[bsipocz]

(I merge as this was already passing before the squash and the current CI issue seems absolutely upstream related)