Posts, Post Types: Fix WP_Query parameter used by get_page_by_title().

Fixes the call to `WP_Query` within `get_page_by_title()` by using the correct title parameter, `title`.

Modify the `orderby` parameter to prioritize the oldest published date over the smallest post ID. This ensures the behaviour matches that of the previous version of `get_page_by_title()`.

The tests have been modified to include a populated post table to ensure the posts returned are matched by design rather than coincidence.

Follow up to [54234].

Props dd32, timothyblynjacobs, peterwilsoncc.
Fixes #56609.
See #36905.



git-svn-id: https://develop.svn.wordpress.org/trunk@54271 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/post.php

@@ -5775,14 +5775,14 @@ function get_page_by_path( $page_path, $output = OBJECT, $post_type = 'page' ) {
  */
 function get_page_by_title( $page_title, $output = OBJECT, $post_type = 'page' ) {
 	$args  = array(
-		'post_title'             => $page_title,
+		'title'                  => $page_title,
 		'post_type'              => $post_type,
 		'post_status'            => get_post_stati(),
 		'posts_per_page'         => 1,
 		'update_post_term_cache' => false,
 		'update_post_meta_cache' => false,
 		'no_found_rows'          => true,
-		'orderby'                => 'ID',
+		'orderby'                => 'post_date ID',
 		'order'                  => 'ASC',
 	);
 	$query = new WP_Query( $args );