Update docs, tests, summaries for stable extensions

[duckontheweb]

Related Issue(s): #

• Implement collection summary functionality #327
• Update extension pydoc strings to match new extension architecture #326

Description:

• Updates API docs for view, projection, and scientific extensions
• Makes doi an optional argument for ScientificExtension and Publication to match spec
• Implements summaries for view, projection, and scientific extensions
• Simplifies summary getter/setter docstrings

stac-fields indicates that JSON Schema format should be used for sci:citation summaries, but using a simple list seemed more appropriate, so that's how I implemented it for now. @m-mohr @matthewhanson Maybe you have more insight around the rationale for using the JSON Schema summaries for that field?

PR Checklist:

• Code is formatted (run scripts/format)
• Tests pass (run scripts/test)
• This PR maintains or improves overall codebase code coverage.
• Changes are added to the CHANGELOG. See the docs for information about adding to the changelog.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 98.54015% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.69%. Comparing base (c62f0fb) to head (0d406d1).
⚠️ Report is 1306 commits behind head on main.

Files with missing lines	Patch %	Lines
pystac/extensions/scientific.py	96.66%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #372      +/-   ##
==========================================
+ Coverage   89.43%   89.69%   +0.26%     
==========================================
  Files          39       39              
  Lines        5063     5154      +91     
==========================================
+ Hits         4528     4623      +95     
+ Misses        535      531       -4     

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[m-mohr]

Yeah, maybe "v" is better as "s" on citation.

We had the case where we had a regexp for the year number in the citation summary, which would be a use case. But I agree that in general, a list of values is probably the better option.

Opened PR stac-utils/stac-fields#11 for it.

[lossyrob]

Looking good, couple of suggestions but overall +1