Menus: Introduce `wp_nav_menu_item_custom_fields` action that fires just before the move buttons of a nav menu item in the menu editor.

Props MikeSchinkel, birgire, sebastian.pisula, desrosj, helgatheviking.
Fixes #47056. See #38904, #18584.
Built from https://develop.svn.wordpress.org/trunk@47190


git-svn-id: http://core.svn.wordpress.org/trunk@46990 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/class-walker-nav-menu-edit.php

@@ -227,6 +227,21 @@ class Walker_Nav_Menu_Edit extends Walker_Nav_Menu {
 					</label>
 				</p>
 
+				<?php
+				/**
+				 * Fires just before the move buttons of a nav menu item in the menu editor.
+				 *
+				 * @since 5.4.0
+				 *
+				 * @param int      $item_id Menu item ID.
+				 * @param WP_Post  $item    Menu item data object.
+				 * @param int      $depth   Depth of menu item. Used for padding.
+				 * @param stdClass $args    An object of menu item arguments.
+				 * @param int      $id      Nav menu ID.
+				 */
+				do_action( 'wp_nav_menu_item_custom_fields', $item_id, $item, $depth, $args, $id );
+				?>
+
 				<fieldset class="field-move hide-if-no-js description description-wide">
 					<span class="field-move-visual-label" aria-hidden="true"><?php _e( 'Move' ); ?></span>
 					<button type="button" class="button-link menus-move menus-move-up" data-dir="up"><?php _e( 'Up one' ); ?></button>

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.4-alpha-47189';
+$wp_version = '5.4-alpha-47190';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.