Administration: Update Site Editor URLs to use path-based format.

Updates Site Editor URLs from legacy query parameters to the new path-based p parameter format. 

Props jabir20, phpbits, sainathpoojary, SirLouen, westonruter, wildworks.
Fixes #63110.

git-svn-id: https://develop.svn.wordpress.org/trunk@61634 602fd350-edb4-49c9-b593-d223f7449a82

Author: t-hamano

src/wp-admin/includes/dashboard.php

@@ -2129,7 +2129,7 @@ function wp_welcome_panel() {
 			<?php if ( $is_block_theme ) : ?>
 				<h3><?php _e( 'Switch up your site&#8217;s look & feel with Styles' ); ?></h3>
 				<p><?php _e( 'Tweak your site, or give it a whole new look! Get creative &#8212; how about a new color palette or font?' ); ?></p>
-				<a href="<?php echo esc_url( admin_url( '/site-editor.php?path=%2Fwp_global_styles' ) ); ?>"><?php _e( 'Edit styles' ); ?></a>
+				<a href="<?php echo esc_url( add_query_arg( 'p', rawurlencode( '/styles' ), admin_url( 'site-editor.php' ) ) ); ?>"><?php _e( 'Edit styles' ); ?></a>
 			<?php else : ?>
 				<h3><?php _e( 'Discover a new way to build your site.' ); ?></h3>
 				<p><?php _e( 'There is a new kind of WordPress theme, called a block theme, that lets you build the site you&#8217;ve always wanted &#8212; with blocks and styles.' ); ?></p>

src/wp-includes/post.php

@@ -359,9 +359,8 @@ function create_initial_post_types() {
 
 	$template_edit_link = 'site-editor.php?' . build_query(
 		array(
-			'postType' => '%s',
-			'postId'   => '%s',
-			'canvas'   => 'edit',
+			'p'      => '/%s/%s',
+			'canvas' => 'edit',
 		)
 	);
 
@@ -531,9 +530,8 @@ function create_initial_post_types() {
 
 	$navigation_post_edit_link = 'site-editor.php?' . build_query(
 		array(
-			'postId'   => '%s',
-			'postType' => 'wp_navigation',
-			'canvas'   => 'edit',
+			'p'      => '/wp_navigation/%s',
+			'canvas' => 'edit',
 		)
 	);