Add outbound tag to tun

[Rambling2076]

Add outbound tag to tun to allow outbound connection go into that tun device

Combined with bridge/portal (reverse proxy), packet to other processes in the operating system can come out from tun with the tun ip instead of 127.0.0.1 when using direct. This will simulate a proper incoming ip for UDP packets, as if it's coming from a real VPN network, making some program like WebRTC happy.