TUN-3617: Separate service from client, and implement different client for http vs. tcp origins

- extracted ResponseWriter from proxyConnection
 - added bastion tests over websocket
 - removed HTTPResp()
 - added some docstrings
 - Renamed some ingress clients as proxies
 - renamed instances of client to proxy in connection and origin
 - Stream no longer takes a context and logger.Service

socks/request_handler.go

@@ -3,6 +3,7 @@ package socks
 import (
 	"fmt"
 	"io"
+	"net"
 	"strings"
 )
 
@@ -104,3 +105,11 @@ func (h *StandardRequestHandler) handleAssociate(conn io.ReadWriter, req *Reques
 	}
 	return nil
 }
+
+func StreamHandler(tunnelConn io.ReadWriter, originConn net.Conn) {
+	dialer := NewConnDialer(originConn)
+	requestHandler := NewRequestHandler(dialer)
+	socksServer := NewConnectionHandler(requestHandler)
+
+	socksServer.Serve(tunnelConn)
+}