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/memberships/product-list.php

@@ -17,7 +17,7 @@
 		href="<?php echo esc_attr(wu_get_form_url('edit_membership_product', ['id' => $membership->get_id()])); ?>"
 		>
 		<span class="dashicons-wu-circle-with-plus wu-align-text-bottom"></span>
-		<?php _e('Add new Product', 'wp-multisite-waas'); ?>
+		<?php esc_html_e('Add new Product', 'wp-multisite-waas'); ?>
 		</a>
 
 	</div>