Administration: Introduce the `manage_posts_extra_tablenav` action, which fires inside the tablenav for the posts list table, and just outside the "actions" container.

Props hlashbrooke, wonderboymusic.
Fixes #30341.


git-svn-id: https://develop.svn.wordpress.org/trunk@35263 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/class-wp-posts-list-table.php

@@ -485,6 +485,15 @@ class WP_Posts_List_Table extends WP_List_Table {
 ?>
 		</div>
 <?php
+		/**
+		 * Fires immediately following the closing "actions" div in the tablenav for the posts
+		 * list table.
+		 *
+		 * @since 4.4.0
+		 * 
+		 * @param string $which The location of the extra table nav markup: 'top' or 'bottom'.
+		 */
+		do_action( 'manage_posts_extra_tablenav', $which );
 	}
 
 	/**