Add API parity stubs for UDP sockets/TCP streams

[progwriter]

These are no-ops in turmoil (AFAICT, based on patterns in our tests), but having these available minimizes the amount of caller code that needs to change

• https://docs.rs/tokio/latest/tokio/net/struct.TcpStream.html#method.set_nodelay
• https://docs.rs/tokio/latest/tokio/net/struct.UdpSocket.html#method.join_multicast_v6
• https://docs.rs/tokio/latest/tokio/net/struct.UdpSocket.html#method.set_multicast_loop_v6

[progwriter]

Done