Add Creative Elements templates and update index files

- Introduced new templates for catalog, checkout, contact, and error pages.
- Implemented caching headers and redirection in index.php files across various directories.
- Enhanced product and layout templates for better integration with Creative Elements.
- Added backoffice header styles and scripts for improved UI/UX in the admin panel.

modules/creativeelements/upgrade/index.php

@@ -0,0 +1,16 @@
+<?php
+/**
+ * Creative Elements - live Theme & Page Builder
+ *
+ * @author    WebshopWorks
+ * @copyright 2019-2022 WebshopWorks.com
+ * @license   One domain support license
+ */
+
+header('Expires: Thu, 28 Feb 2019 00:00:00 GMT');
+header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT');
+header('Cache-Control: no-store, no-cache, must-revalidate, max-age=0');
+header('Cache-Control: post-check=0, pre-check=0', false);
+header('Pragma: no-cache');
+header('Location: ../../../');
+die;