REST API: Bring new endpoints for Block Patterns from Gutenberg plugin
Related Gutenberg issue: https://github.com/WordPress/gutenberg/issues/39889.
Backporting changes from the Gutenberg plugin:
- new Block Patterns REST API endpoint
- new Block Pattern Categories REST API endpoint
- updates to Query Loop related patterns
- support for custom taxonomies in Query Loop block
Props hellofromtonya, peterwilsoncc, ntsekouras, zieladam, ironprogrammer, spacedmonkey, timothyblynjacobs, antonvlasenko, jsnajdr.
See #55505.