REST API: Support uuid json schema format

[TimothyBlynJacobs]

We should add support for format: "uuid" in rest_validate_value_from_schema. We can use the existing wp_is_uuid function for validation. And I'd imagine sanitize_text_field for sanitization.

At the moment, I think we can skip checking for a specific uuid version.

The list of formats is extensible, but uuid is also included as a format in the ​latest specs.

https://core.trac.wordpress.org/ticket/50053

This adds support for the uuid format in WP REST JSON schema. As suggested in the ticket description, the format is validated with wp_is_uuid and sanitized with sanitize_text_field.

[TimothyBlynJacobs]

In 47753:

REST API: Support the uuid JSON Schema format.

This accepts a uuid of any version. A future commit could add support for restricting uuids to a specific version.

Props johnwatkins0.
Fixes #50053.

Merged in ef05acd, [r47753](https://core.trac.wordpress.org/changeset/47753).

Thanks, @TimothyBJacobs !

[TimothyBlynJacobs]

In 47811:

REST API: Add @since entries for rest_validate_value_from_schema().

See #49572, #48818, #44949, #50053, #48820, #49720, #42961, #44975, #43392, #38583.