MAPG-235 created error handling for challenge access without login

src/Controller/GameController.php

@@ -97,7 +97,7 @@ class GameController
     }
 
     public function getChallenge(): IContent
-    {
+    {   
         $challengeToken = $this->request->query('challengeToken');
 
         return new HtmlContent('game', ['challengeToken' => $challengeToken]);
@@ -239,8 +239,19 @@ class GameController
         $challengeToken_str = $this->request->query('challengeToken');
         $session = $this->request->session();
         $userId = $session->get('userId');
+
+        if (!isset($userId))
+        {
+            return new JsonContent(['error' => 'anonymous_user']);
+        }
+
         $challenge = $this->challengeRepository->getByTokenStr($challengeToken_str);
 
+        if (!isset($challenge))
+        {
+            return new JsonContent(['error' => 'game_not_found']);
+        }
+
         if(!$this->userInChallengeRepository->isUserParticipatingInChallenge($userId, $challenge)) {
             // new player is joining
             $userInChallenge = new UserInChallenge();