Function session 

async fn session(
    ep: &Endpoint,
    ep_rx: &mut Receiver<Option<Endpoint>>,
    act_rx: &mut UnboundedReceiver<UserAction>,
    presenter: &Arc<dyn Presenter>,
    data_dir: &Path,
    dir_hash: &str,
    state: &Arc<Mutex<State>>,
) -> SessionEnd