Vendors: Add missing CSRF, need to update the permissions as a vendor can be client or global and permissions need to be set based off if the referal url has client_id or not

agent/modals/vendor/vendor_export.php

@@ -15,6 +15,7 @@ ob_start();
     </button>
 </div>
 <form action="post.php" method="post" autocomplete="off">
+    <input type="hidden" name="csrf_token" value="<?= $_SESSION['csrf_token'] ?>">
     <input type="hidden" name="client_id" value="<?= $client_id ?>">
 
     <div class="modal-body">