Add migration for pre-1.0.0-rc.1 Stats Object

[duckontheweb]

Related Issue(s): #

• Closes Add migration for change in summaries properties #330

PR Checklist:

• Code is formatted (run pre-commit run --all-files)
• 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

Merging #447 (e7eb186) into main (e7d4bdc) will increase coverage by 0.12%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #447      +/-   ##
==========================================
+ Coverage   90.67%   90.79%   +0.12%     
==========================================
  Files          40       40              
  Lines        5105     5119      +14     
==========================================
+ Hits         4629     4648      +19     
+ Misses        476      471       -5     

Impacted Files	Coverage Δ
pystac/serialization/migrate.py	87.30% <100.00%> (+1.33%)	⬆️
pystac/summaries.py	78.84% <0.00%> (+0.64%)	⬆️
pystac/stac_io.py	76.71% <0.00%> (+4.24%)	⬆️

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[duckontheweb]

The coverage on summaries.py is dropping because the old "min"/"max" Stats Object were being handled as JSON Schema Objects instead of Range Objects prior to this PR. Now that they are handled properly, we do not have any example Collections that use JSON Schema Objects in their summaries (at least that I could find). The only properties that stac-fields marks as using Schema Objects for summaries are "sci:citation", "sentinel:product_id", and "pc:statistics", but I could not find any examples in this repo or the Point Cloud or Scientific Extensions repos.

@m-mohr I'm honestly just having a hard time getting my head around what a JSON Schema Object in a summary should look like. Do you have an example for any of the fields listed here?

[lossyrob]

This issue is where the summary JSON schema object was discussed, the bottom gives some examples: radiantearth/stac-spec#1045, and resulted in PR radiantearth/stac-spec#1093

There's an example for resto: summaries in https://github.com/radiantearth/stac-spec/blob/master/examples/collection-only/collection-with-schemas.json