message: Set NextBatchInfo in PendingTxsStorage response
diff: @@ -100,6 +100,7 @@ namespace iroha {
  auto &txs = batch_iterator->get()->transactions();
  next_batch_info.first_tx_hash = txs.front()->hash();
  next_batch_info.batch_size = txs.size();
  + response.next_batch_info = std::move(next_batch_info);
  }
  return iroha::expected::makeValue(std::move(response));
  }
  