`use_block_editor_for_post()` and `use_block_editor_for_post_type()` determine if the block editor should be loaded.
`get_block_categories()` and `get_block_editor_server_block_settings()` provide data be included while the block editor is loading.
Props pento.
Merges [43762] to trunk.
See #45110.
Built from https://develop.svn.wordpress.org/trunk@44122
git-svn-id: http://core.svn.wordpress.org/trunk@43952 1a063a9b-81f0-0310-95a4-ce76da25c4cd