Backport fixes for wp/v2/block-patterns/patterns and /wp/v2/pattern-directory/patterns endpoints to Gutenberg

[anton-vlasenko]

What problem does this address?

There have been 3 Core PRs that fixed a number of issues related to wp/v2/block-patterns/patterns and /wp/v2/pattern-directory/patterns endpoints.
These PRs have to be backported back to Gutenberg:

• Backport WP_REST_Pattern_Directory_Controller::get_items doesn't support array arguments wordpress-develop#2591
• Backport /wp/v2/pattern-directory/patterns endpoint: slug parameter has no effect on the response wordpress-develop#2625
• Backport Don't load remote patterns twice in WP_REST_Block_Patterns_Controller::get_items wordpress-develop#2576

[ndiego]

@gziolo looking for some guidance here. This issue and the associated PRs backport some last-minute changes that made it into 6.0. These changes were never added back to Gutenberg itself. I am about to put together a PR that fixes #41282 but it relies on the PRs associated with this issue being backported. I cannot think of a reason we wouldn't want to backport these to Gutenberg, unless I am missing something. Thanks for your insight 🙏

[gziolo]

Yes, we definitely should bring back all those changes to the Gutenberg plugin. @ndiego, I had some time off so I haven't seen your message earlier. We always bring back to the plugin all changes applied in WordPress core in case we have matching functionality for previous versions of WordPress.

[ndiego]

@gziolo no worries, hope you enjoyed your time off!

[anton-vlasenko]

I'm reopening this issue because #40900 is not merged yet.
GitHub automatically closed this issue, but it should remain open until #40900 is merged.