Add function to check if request is auto refresh

Add a function to the Icinga Web Request that checks whether the
request is sent by auto refresh by checking if the request header
`X-Icinga-Autorefresh` is set.

Author: jrauh01

library/Icinga/Web/Request.php

@@ -3,10 +3,10 @@
 
 namespace Icinga\Web;
 
-use Icinga\Util\Json;
-use Zend_Controller_Request_Http;
 use Icinga\Application\Icinga;
 use Icinga\User;
+use Icinga\Util\Json;
+use Zend_Controller_Request_Http;
 
 /**
  * A request
@@ -101,6 +101,16 @@ public function isApiRequest()
         return $this->getHeader('Accept') === 'application/json';
     }
 
+    /**
+     * Get whether the request is sent by auto refresh
+     *
+     * @return bool
+     */
+    public function isAutoRefresh(): bool
+    {
+        return $this->getHeader('X-Icinga-Autorefresh');
+    }
+
     /**
      * Makes an ID unique to this request, to prevent id collisions in different containers
      *