Accept StompCommandListener constructor or instance when building Sessions

[pcan]

The createStompServerSession and createStompClientSession should also accept a StompCommandListener constructor in order to build a listener that accept a reference to the newly created session. With this enhancement the following code will be possible:

class MyListener implements StompClientCommandListener {

    constructor(private readonly session: StompServerSessionLayer) {
    }

    connect(headers?: StompHeaders): void {
        this.session.connected({ version: '1.2', server: 'MyServer/1.8.2' }).catch(console.error);
    }

    // other methods implemented here...
}

const session = createStompServerSession(socket, MyListener);