Add PayPal webhook handler and marketing styles

- Implemented PayPal webhook for handling payment notifications, including signature verification and transaction updates.
- Created invoice generation and license management for software upgrades upon successful payment.
- Added comprehensive logging for debugging purposes.
- Introduced new CSS styles for the marketing file management system, including layout, toolbar, breadcrumb navigation, search filters, and file management UI components.

api/v2/get/equipments.php

@@ -275,7 +275,7 @@ else {
    }
   
     //SQL for Paging 
-    $sql = 'SELECT e.rowID as equipmentID, e.*, p.productcode, p.productname, p.product_media from equipment e LEFT JOIN products p ON e.productrowid = p.rowID '.$whereclause.' ORDER BY '.$sort.' LIMIT :page,:num_products';
+    $sql = 'SELECT e.rowID as equipmentID, e.*, p.productcode, p.productname, p.product_media, psl.starts_at,psl.expires_at,psl.status as license_status from equipment e LEFT JOIN products p ON e.productrowid = p.rowID LEFT JOIN products_software_licenses psl ON e.sw_version_license = psl.license_key '.$whereclause.' ORDER BY '.$sort.' LIMIT :page,:num_products';
 }
 
 $stmt = $pdo->prepare($sql);