Update JSON schemas to use draft-07

[ajlende]

We've been following the SchemaStore best practices for the development of our JSON schemas. They recommend a schema version based on what is widely supported in editors and IDEs. Previously this was draft-04, so all of our schemas currently use that version. However the new recommendation is draft-07 which comes with some quality of life improvements that can improve the readability and maintainability of our JSON schemas. Namely:

1. The $comment keyword to explain reasoning behind schema decisions inline.
2. The propertyNames keyword to improve merging of two or more object subschemas while limiting additionalProperties.

Additionally, SchemaStore has an unofficial "strict mode" draft-07 meta schema https://json.schemastore.org/metaschema-draft-07-unofficial-strict.json that requires type, title, and description properties which we should be using and provides links to understanding-json-schema for each hint/check to help new JSON Schema contributors.

• There are some breaking changes from draft-04 to draft-06. You can migrate schemas from draft-04 to draft-07 using ajv-cli.
• The pattern of *PropertiesComplete can be updated to use propertyNames instead of lists of empty objects.
• The enum properties with single values can be updated to const where it would make sense to use const.

[DivyanshVinayak23]

Hi, can I work on this?

[ajlende]

Hi, can I work on this?

@DivyanshVinayak23 Absolutely!

Check out the contributing guidelines, specifically the developer section, for general information on how to contribute code.

The #core-editor channel on Make WordPress Slack (registration required) is also a good place to ask questions if you have any.

[scruffian]

I noticed we use the ajv-draft-04 npm package, and I can't find an alternative for draft-07...

[ajlende]

I noticed we use the ajv-draft-04 npm package, and I can't find an alternative for draft-07...

The draft-07 validator is in the main ajv package. Because there were breaking changes, they made the draft-04 validator its own package.