Instead of providing a `ready` promise, use an async factory function about sockets-api

[jasnell]

While I like this approach, the API pattern seems potentially less ergonomic for the server side. Specifically, in the following case: is the socket already in the ready state when the event is emitted?

addEventListener('socket', ({socket}) => {
  // is the socket already ready?
});

If it's not already in the ready state, what does the user do in the very rare cases where it might need to wait for the socket to be in a ready state before performing any actions on it (shouldn't be common at all but still worth considering...

If the socket is already in the ready state, what defines "ready" when we're talking about a TLS connection where the user-code may want to interact with the TLS handshake somehow? For instance, in Node.js' existing api there are ways to hook the client hello, providing an OCSP response, selecting a pre-shared key, etc.