message: Fix TOM.ModelOperationResult.ThrowOnError
diff: public static void ThrowOnError(this TOM.ModelOperationResult operationResult)
  {
  - if (operationResult.XmlaResults is not null)
  + if (operationResult.XmlaResults?.ContainsErrors == true)
  {
  var message = operationResult.ToDescriptionString();
  throw new BravoException(BravoProblem.TOMDatabaseUpdateFailed, message!);
  