REST API endpoints for sites

[lloc]

Trac ticket: https://core.trac.wordpress.org/ticket/40365

There are some open questions that we should discuss in the trac ticket.

[github-actions]

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[github-actions]

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[jonnydmg]

There is a big PR to review. Good work getting this ready for core. This code a little old and some things have changed in core, so this PR needs to update accordingly.

Biggest things.

• We need to support sites with is_site_meta_supported false. There was some work done there to support it but not complete.
• Site endpoint needs to be registered on single site. So it always exists then return an error on single site.
• WP_REST_Site_Meta_Fields has no test coverage at all.
• Single site needs tests.
• Super admin should be allowed to do everything on the endpoint.
• Code coverage and ticket need needs to be added to every test.

This feel like we are on the right track, if I am nitpicing here, becuase I think this good to go into core and just want to get the final bits to push forward into core.

I will wait until feedback is complete to do some real testing for this PR.

[jonnydmg]

We should have another test file for with all the tests related to it not being multisite, as there are lots of checks for is_mulitiste. There are so many this feels like a good fit for another file instead of excloding each test one at a time.

[jonnydmg]

There is a big PR to review. Good work getting this ready for core. This code a little old and some things have changed in core, so this PR needs to update accordingly.

Biggest things.

• We need to support sites with is_site_meta_supported false. There was some work done there to support it but not complete.
• Site endpoint needs to be registered on single site. So it always exists then return an error on single site.
• WP_REST_Site_Meta_Fields has no test coverage at all.
• Single site needs tests.
• Super admin should be allowed to do everything on the endpoint.
• Code coverage and ticket need needs to be added to every test.

This feel like we are on the right track, if I am nitpicing here, becuase I think this good to go into core and just want to get the final bits to push forward into core.

I will wait until feedback is complete to do some real testing for this PR.