Global styles revisions: add route for single styles revisions

[ramonjd]

For awareness, some of these changes can be merged with this PR:

• Global styles controllers: extend with WP_REST_Posts_Controller and WP_REST_Revisions_Controller  #5699

What?

Syncing Gutenberg PR:

• Global styles revisions: add route for single styles revisions gutenberg#55827

Adding route for single global styles revisions: /wp/v2/global-styles/${ parentId }/revisions/${ revisionsId }

Why?

To make global styles revisions compatible with the proposed Core Data revisions API, that is, so that we can fetch single revisions via getRevision().

Trac ticket: https://core.trac.wordpress.org/ticket/59810

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This Pull Request is for code review only. Please keep all other discussion in the Trac ticket. Do not merge this Pull Request. See GitHub Pull Requests for Code Review in the Core Handbook for more details.

[youknowriad]

@ramonjd Is it possible to add a unit test for this?

[getdave]

@ramonjd Is it possible to add a unit test for this?

I see unit tests in this PR.

npm run test:php -- --filter WP_REST_Global_Styles_Revisions_Controller_Test

OK (28 tests, 107 assertions)

What am I missing?

[youknowriad]

What am I missing?

That my brain is confused with too many tabs maybe :P

You're right there are unit tests.

[ramonjd]

Thanks for double checking, folks!

[youknowriad]

Commit https://core.trac.wordpress.org/changeset/57494