REST API: Add missing options to the settings endpoint

[Mamaduka]

PR registers options for the settings endpoints. Unfortunately, we missed them during WP 6.0 backports - WordPress/gutenberg#38607 (comment).

Testing Instructions

1. Open a Post or Page editor.
2. Run this snippet in the DevTools console - wp.data.select('core').getEntityRecord( 'root', 'site' );
3. Confirm newly registered settings are returned.

Trac ticket: https://core.trac.wordpress.org/ticket/56058

---

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

[Mamaduka]

I'm not sure how to fix the remaining failure. Is there a command for regenerating API fixtures?

[spacedmonkey]

@Mamaduka If you run the tests locally, but running npm run test:php, it should regenerate that file. Just it and push it and it will fix the tests.

[spacedmonkey]

Looks good to me.

[SergeyBiryukov]

Thanks for the PR!

This was merged to WP trunk in https://core.trac.wordpress.org/changeset/53588, but I noticed that the new options are the only ones in register_initial_settings() that use the number type instead of integer. If I'm reading it correctly, that means they can technically be floats. Since both page_on_front and page_for_posts are page IDs, should they be integer?

[Mamaduka]

Thanks for catching that, @SergeyBiryukov 🙇

[SergeyBiryukov]

I've made a follow-up commit that switches the type to integer as per the comment above :)

[SergeyBiryukov]

Thanks for the confirmation that it was OK to change the type :) Merged in https://core.trac.wordpress.org/changeset/53589.

Backported to the 6.0 branch in https://core.trac.wordpress.org/changeset/53590.