MAPG-235 new challenge can be created and is prepared

src/Repository/ChallengeRepository.php

@@ -28,6 +28,13 @@ class ChallengeRepository
         return $this->pdm->selectFromDb($select, Challenge::class);
     }
 
+    public function getByTokenStr(string $token_str): ?Challenge
+    {
+        $token = hexdec($token_str);
+
+        return $this->getByToken($token);
+    }
+
     public function getAllByParticipant(User $user): Generator
     {
         $select = new Select(\Container::$dbConnection);