update storage extension to v2.0.0

[tylanderson]

Description:

Updates storage extension to v2.0.0. Due to the major changes in v2, I have not attempted to make migrations from v1 to v2

StorageScheme platform property allows templated uri's, so arbitrary additional properties are allowed to be set on StorageScheme objects

PR Checklist:

• Pre-commit hooks pass (run pre-commit run --all-files)
• Tests pass (run pytest)
• 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.

[codecov]

Codecov Report

❌ Patch coverage is 91.54229% with 17 lines in your changes missing coverage. Please review.
✅ Project coverage is 92.27%. Comparing base (608972a) to head (8d5e996).

Files with missing lines	Patch %	Lines
pystac/extensions/storage.py	91.14%	15 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1561      +/-   ##
==========================================
- Coverage   92.29%   92.27%   -0.02%     
==========================================
  Files          55       55              
  Lines        8395     8519     +124     
  Branches      971      984      +13     
==========================================
+ Hits         7748     7861     +113     
- Misses        458      468      +10     
- Partials      189      190       +1     

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[gadomski]

I think we have unnecessary new extensions here ... both schemes and refs can just be classes, not extensions themselves?

[thomas-maschler]

Can you also add GCS = "gcp-gs"

[thomas-maschler]

generally, having parity to the v1 Enum would be great

[tylanderson]

I didn't see best practice GCP storage defined here, so did not add as a possible enum here, but as written schemes can be set to any string. I think opening a PR in the extension w/ a suggested schema to use for GCP storage would make sense before implemented here.