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/base/wizard/submit-box.php

@@ -9,13 +9,13 @@
 <div class="wu-flex wu-justify-between wu-bg-gray-100 wu--m-in wu-mt-4 wu-p-4 wu-overflow-hidden wu-border-t wu-border-solid wu-border-l-0 wu-border-r-0 wu-border-b-0 wu-border-gray-300">
 
 	<a href="<?php echo esc_url($page->get_prev_section_link()); ?>" class="wu-self-center button button-large wu-float-left">
-	<?php _e('&larr; Go Back', 'wp-multisite-waas'); ?>
+	<?php esc_html_e('← Go Back', 'wp-multisite-waas'); ?>
 	</a>
 
 	<span class="wu-self-center wu-content-center wu-flex">
 
 	<button name="submit" value="1" class="button button-primary button-large">
-		<?php _e('Continue', 'wp-multisite-waas'); ?>
+		<?php esc_html_e('Continue', 'wp-multisite-waas'); ?>
 	</button>
 
 	</span>