Break wp_print_media_templates() into wp-includes/media-template.php and...

Break wp_print_media_templates() into wp-includes/media-template.php and lazy-load that file through wp_enqueue_media(). fixes #22778.



git-svn-id: https://core.svn.wordpress.org/trunk@23101 1a063a9b-81f0-0310-95a4-ce76da25c4cd