Prep Plugin for release on WordPress.org

Escape everything that should be escaped.
Add nonce checks where needed.
Sanitize all inputs.
Apply Code style changes across the codebase.
Correct many deprecation notices.
Optimize load order of many filters.

views/legacy/signup/pricing-table/no-plans.php

@@ -22,5 +22,5 @@ if ( ! defined('ABSPATH')) {
 ?>
 
 <div class="wu-setup-content-error">
-	<p><?php _e('There are no Plans created in the platform.', 'wp-multisite-waas'); ?></p><br>
+	<p><?php esc_html_e('There are no Plans created in the platform.', 'wp-multisite-waas'); ?></p><br>
 </div>