WebSocket support for kofu

[cromefire]

While you can simply do normal http requests like this:

GET("/") {
    // ...
}

There does not seem to be a WebSocket equivalent like:

webSocket("/") {
    // ...
}

Ktor supports it like this for example:

webSocket("/socket") {
    outgoing.send(Frame.Text("{}"))
    for (frame in incoming) {
        // ...
    }
}

There seem to be some workarounds, but they aren't very ideal