[coro_http][feat]coro_http_server support websocket

[qicosmos]

Why

  coro_http::coro_http_server server(1, 9001);
  server.set_http_handler<cinatra::GET>(
      "/ws_echo",
      [](coro_http_request &req,
         coro_http_response &resp) -> async_simple::coro::Lazy<void> {
        assert(req.get_content_type() == content_type::websocket);
        std::string out_str;
        websocket_result result{};
        while (!result.eof) {
          result = co_await req.get_conn()->read_websocket();
          if (result.ec) {
            break;
          }

          if (result.type == ws_frame_type::WS_CLOSE_FRAME) {
            std::cout << "close frame\n";
            break;
          }

          out_str.append(result.data);

          auto ec = co_await req.get_conn()->write_websocket(result.data);
          if (ec) {
            continue;
          }
        }

        std::cout << out_str << "\n";
      });

  server.async_start();

What is changing

Example