message: support TypeCmd
diff: @@ -1023,7 +1023,7 @@ void TypeCmd::DoInitial(PikaCmdArgsType &argv, const CmdInfo* const ptr_info) {
  void TypeCmd::Do() {
  std::string res;
  - nemo::Status s = g_pika_server->db()->Type(key_, &res);
  + rocksdb::Status s = g_pika_server->bdb()->Type(key_, &res);
  if (s.ok()) {
  res_.AppendContent("+" + res);
  } else {
  