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.
git-svn-id: https://develop.svn.wordpress.org/trunk@51021 602fd350-edb4-49c9-b593-d223f7449a82