MQTT/UNS Debug Mode

Within our topic hierarchy view, it would be valuable to "watch" a given topic to assist with debugging. Loosely, have a "debug" option on each topic, when active, the screen then shows a thread type interface for messages received when subscribing.

I suspect we'd need an MQTT client setup on the server-side or this, and then broker the traffic to the UI? Not sure if we have browser-side option?