Editor: Revert [48119].

This commit caused the majority of blocks in the block editor to no longer
register as they reference the old category names.

See #50278.

Built from https://develop.svn.wordpress.org/trunk@48130


git-svn-id: https://core.svn.wordpress.org/trunk@47899 1a063a9b-81f0-0310-95a4-ce76da25c4cd