Accessibility: Make sure layout tables across the admin are correctly linearized.

Adds `role="presentation"` to the `<table>` elements used for layout purposes.

Ideally, HTML tables should be used for tabular data. When tables are used for layout purposes, it's important to remove any native semantics so that assistive technologies can correctly announce the table content in a linearized fashion.

Props greatislander, afercia.
Fixes #46899.

git-svn-id: https://develop.svn.wordpress.org/trunk@45403 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/options-writing.php

@@ -62,7 +62,7 @@ include( ABSPATH . 'wp-admin/admin-header.php' );
 <form method="post" action="options.php">
 <?php settings_fields( 'writing' ); ?>
 
-<table class="form-table">
+<table class="form-table" role="presentation">
 <?php if ( get_site_option( 'initial_db_version' ) < 32453 ) : ?>
 <tr>
 <th scope="row"><?php _e( 'Formatting' ); ?></th>
@@ -150,7 +150,7 @@ if ( apply_filters( 'enable_post_by_email_configuration', true ) ) {
 	?>
 </p>
 
-<table class="form-table">
+<table class="form-table" role="presentation">
 <tr>
 <th scope="row"><label for="mailserver_url"><?php _e( 'Mail Server' ); ?></label></th>
 <td><input name="mailserver_url" type="text" id="mailserver_url" value="<?php form_option( 'mailserver_url' ); ?>" class="regular-text code" />