Editor: Preload REST API requests fetched on editor load.

Add four entries to the block editor preload paths in `wp-admin/edit-form-blocks.php`: the front-page template lookup, the taxonomies list, the `OPTIONS` permissions request for the post type collection, and, for post types that support it, the post author's display name. The editor previously requested all of these over the network on first load.

Developed in WordPress#11948.

Props ellatrix, mamaduka.
Fixes #65636.


git-svn-id: https://develop.svn.wordpress.org/trunk@62749 602fd350-edb4-49c9-b593-d223f7449a82

Author: ellatrix

src/wp-admin/edit-form-blocks.php

@@ -115,8 +115,18 @@ static function ( $classes ) {
 		$template_lookup_slug,
 		'/wp/v2/templates/lookup'
 	),
+	'/wp/v2/templates/lookup?slug=front-page',
+	'/wp/v2/taxonomies?context=edit',
+	array( rest_get_route_for_post_type_items( $post_type ), 'OPTIONS' ),
 );
 
+if ( post_type_supports( $post_type, 'author' ) && $post->post_author > 0 ) {
+	$preload_paths[] = sprintf(
+		'/wp/v2/users/%d?context=view&_fields=id,name',
+		(int) $post->post_author
+	);
+}
+
 block_editor_rest_api_preload( $preload_paths, $block_editor_context );
 
 wp_add_inline_script(