InvalidQueryForm's detail is now complete.

The detail of InvalidQueryForm is now constructed recursively, thus including all children errors instead of just the first level (ie fields).

Sample response : 

    {
        "problemType": "http://not-specified-yet",
         "title": "Invalid query",
         "detail": {
         "formErrors": {
             "deliveryTimeSlot": {
                 "ending": [
                         "A timeslot should end after it has started."
                    ]
                }
            }
        }
    }