Changeset 51021 for trunk/src/wp-includes/rest-api/endpoints/class-wp-rest-pattern-directory-controller.php

Block Editor: Add support for the pattern directory.

Add an endpoint for fetching block patterns from WordPress.org, and load the block patterns from this new API. Remove the block patterns that have already been moved to WordPress.org/patterns.

Props ryelle, iandunn, youknowriad, timothyblynjacobs.
Fixes #53246.