Add a mechanism for adding headers to StacIO requests

[john-dupuy]

Related Issue(s): #886

Description:
This PR aims to address #886 by adding a mechanism for adding headers for StacIO requests.

The suggested approach for using this:

from pystac import StacIO
stac_io = StacIO.default()
stac_io.headers = {"Authorization": "<some-authn-header>"}

catalog = Catalog.from_file("<some-href-that-requires-authn>", stac_io=stac_io)

You could also just directly instantiate the StacIO or DefaultStacIO class, with headers included as an arg.

PR Checklist:

• Code is formatted (run pre-commit run --all-files)
• Tests pass (run scripts/test)
• Documentation has been updated to reflect changes, if applicable
• 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.

[john-dupuy]

@gadomski can you take a look?

[gadomski]

@gadomski can you take a look?

Yes, it's in my queue, thanks for the bump. Right now I'm working on PySTAC issues in my off time so responses may be a bit slower, apologies.

[codecov-commenter]

Codecov Report

Base: 94.29% // Head: 94.31% // Increases project coverage by +0.01% 🎉

Coverage data is based on head (7bd8605) compared to base (8b2a540).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #889      +/-   ##
==========================================
+ Coverage   94.29%   94.31%   +0.01%     
==========================================
  Files          80       80              
  Lines       11909    11922      +13     
  Branches     1130     1130              
==========================================
+ Hits        11230    11244      +14     
  Misses        496      496              
+ Partials      183      182       -1     

Impacted Files	Coverage Δ
pystac/stac_io.py	87.82% <100.00%> (+0.43%)	⬆️
tests/test_stac_io.py	100.00% <100.00%> (ø)
pystac/catalog.py	91.34% <0.00%> (+0.24%)	⬆️

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[gadomski]

I've tested this with a real-world STAC server that requires authorization, and it appears to work. Thanks for the contribution! I'm going to request @matthewhanson's review as well, because he brought up the point in a side channel that you could just use pystac-client, which already supports authorization. In my opinion, this PR is still useful, as it doesn't add any extra dependencies to add functionality, but would like Matt to weigh in as well.

[matthewhanson]

Thanks for the PR @john-dupuy . As @gadomski said, you could use pystac-client here which handles header auth and works fine on static catalogs. However I agree that since it requires no dependencies and is a simple addition it doesn't hurt to include it in PySTAC as well.