Implement private swarms

[rklaehn]

Use rust-libp2p pnet optionally

https://github.com/libp2p/rust-libp2p/tree/master/transports/pnet

I seem to remember that I wrote this and go tomaka to merge it, but blame does not have me anymore, not even tomaka. 🤷‍♂️

[dignifiedquire]

We need to plan to be able to be part of multiple of these. This might require changes in libp2p.

[rklaehn]

This is one of the things needed for actyx.com to be able to use iroh-embed as a replacement for ipfs-embed.

[rklaehn]

So adding this for tcp and websocket is straightforward. Adding it for quic is not.

The issue is that this relies on the socket being AsyncRead and AsyncWrite, which the quic socket is not.

In TCP the private net stuff goes here

• transport
• pnet <===
• muxer

But in quic you already get a muxer thingie out.

    /// upgrade a connection to use pre shared key encryption.
    ///
    /// the upgrade works by both sides exchanging 24 byte nonces and then encrypting
    /// subsequent traffic with XSalsa20
    pub async fn handshake<TSocket>(

        self,
        mut socket: TSocket,
    ) -> Result<PnetOutput<TSocket>, PnetError>

[rkuhn]

cf. libp2p/specs#489