feat: add rtmp client session timeout option

[vaptu]

The timeout that can be used for supported RTMP pull.

The ClientSession provides a set_timeout function that allows setting a customizable timeout.

e.g.

let mut client_session = ClientSession::new(
    stream,
    ClientSessionType::Pull,
    address.clone(),
    app_name.clone(),
    stream_name.clone(),
    producer.clone(),
    0,
);

// set timeout
client_session.set_timeout((Duration::from_secs(3));

[harlanc]

thanks.