Add release-specific release.json files

[richlander]

Fixes #9417.

Improvements:

• Add READMEs for new content
• Generate releases-index.json
• Generate patch-releases-index.json, per release
• Generate release.json, per patch release
• Update releases.json, per major release, to include all the required information for generating the other files
• Generate/add schemas for all JSON formats
• Add $schema reference to JSON files

Notes:

• I only generated the fancy new files for releases in-support. That had the benefit of making it so that the algorithm doesn't continue to re-generate these files for releases no longer generating new content.
• I didn't add a schema reference to the generated files, both because it doesn't seem necessary (no edits are intended) and I do not know how.
• I'll add os-packages.json files for .NET 6 and 8 in a later PR.

@Falco20019 @martincostello @leecow

[richlander]

I think I got all of that @martincostello. Thanks much!

The formats file still needs some help.

I'll make another PR to update the link forwards in release-index.json in another PR.

[richlander]

I believe that this PR is ready to go.

Much of this is based on an OM I built, which is the basis of the schema generation and the serializer for release.json. I did a test where I deserialized and then serialized releases.json and then used a json diff tool to see how before and after compared. The test passed. I also validated the files with these new schema. That also seems to pass (you can test this yourself).

We need to wait for @leecow to validate the following changes:

• Updates to releases-index.json and releases.json files
• Addition of patch-releases-index.json and release.json files

These all need to be uploaded/updated in blob storage before merging.

We should also double check that everyone is good with the new property and file names.

[Falco20019]

See some comments on richlander/distroessed#5 (review) for changes to the generated schemas. Usually, schemas also do set "additionalProperties": false to make it clear that there are no additional fields allowed in the JSON. Not fully required, but would make intention more clear.

[Falco20019]

Add the $schema.

[richlander]

I'm not sure if System.Text.Json supports those things.

@eiriktsarpalis

[eiriktsarpalis]

By default STJ allows additional properties which is reflected in the generated schema. This setting can be overridden using the JsonUnmappedMemberHandlingAttribute.

[richlander]

I made this update.

e868532

[richlander]

I had to do process a merge conflict due to #9424. I knew that would happen, but that's how it goes.

[richlander]

This work will be broken into multiple PRs.