[Request] add UDP proxying support for SOCKS5 connector

Use case

Proxy all traffic (UDP+TCP) incoming on TUNGO interface through a SOCKS5 proxy.

Config file

Note: $IP, $PORT and $PROTO are templated using external tool, don't mind them. $PROTO is always "socks5".

services:
  - name: tungo-0
    addr: :0
    handler: {type: tungo, chain: chain-0}
    listener: {type: tungo, metadata: {name: tungo, net: 192.168.0.1/24}}
chains:
  - name: chain-0
    hops:
      - name: hop-0
        nodes:
          - name: node-0
            addr: $IP:$PORT
            connector: {type: $PROTO}
            dialer: {type: tcp}

What I've tried

I've tried to change the dialer's type to UDP (failed: only SSU connector supports UDP).

I've tried to change connector: {type: $PROTO} to connector: {type: $PROTO, metadata: {udp: true}} which had no effect.