add support for hysteria udp port hopping (#269)

* add support for hysteria udp port hopping

* add ports field for hysteria

* change method for udp connection

Co-authored-by: geoleonsh <geoleonsh@live.com>

transport/hysteria/utils/misc.go

@@ -1,6 +1,7 @@
 package utils
 
 import (
+	"context"
 	"net"
 	"strconv"
 )
@@ -40,3 +41,9 @@ func last(s string, b byte) int {
 	}
 	return i
 }
+
+type PacketDialer interface {
+	ListenPacket() (net.PacketConn, error)
+	Context() context.Context
+	RemoteAddr(host string) (net.Addr, error)
+}