Editor: Add item_updated label for wp_template and `wp_template_p…

…art` post types.

This adds the `item_updated` label to Template and Template Part post types registration. This prevents from displaying the default `post updated` label.
See WordPress/gutenberg#61146 

Follow-up to [52062], [51003].

Props ntsekouras, ellatrix.
Fixes #61095.




git-svn-id: https://develop.svn.wordpress.org/trunk@58055 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/post.php

@@ -365,6 +365,7 @@ function create_initial_post_types() {
 				'filter_items_list'     => __( 'Filter templates list' ),
 				'items_list_navigation' => __( 'Templates list navigation' ),
 				'items_list'            => __( 'Templates list' ),
+				'item_updated'          => __( 'Template updated.' ),
 			),
 			'description'                     => __( 'Templates to include in your theme.' ),
 			'public'                          => false,
@@ -429,6 +430,7 @@ function create_initial_post_types() {
 				'filter_items_list'     => __( 'Filter template parts list' ),
 				'items_list_navigation' => __( 'Template parts list navigation' ),
 				'items_list'            => __( 'Template parts list' ),
+				'item_updated'          => __( 'Template part updated.' ),
 			),
 			'description'                     => __( 'Template parts to include in your templates.' ),
 			'public'                          => false,