Add initial files and templates for Omnibus EU Free module

- Added yt_logo.png image for branding.
- Created index.php for views and templates with license notice and redirection.
- Implemented back.js for reload functionality with event listener.
- Developed configure.tpl for admin configuration panel with documentation links.
- Established products-price-list.tpl for displaying product pricing information.
- Created presta_studio_omnibus_price.tpl for displaying price history and discounts.
- Added index.php files in various directories for consistent redirection and license notice.

modules/omnibuseufree/views/css/omnibuseufree-presta-studio.css

@@ -0,0 +1,17 @@
+/**
+*
+* NOTICE OF LICENSE
+*
+* This source file is subject to the Apache License, Version 2.0
+* that is bundled with this package in the file LICENSE.
+* It is also available through the world-wide-web at this URL:
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+*  @author    presta.studio
+*  @copyright Copyright (c) 2023 presta.studio
+*  @license   http://www.apache.org/licenses/LICENSE-2.0  Apache License, Version 2.0
+*/
+.presta-studio-price-history .presta-studio-price-history-text{
+    color: #000000;
+    font-size: 0.875rem;
+}