Improve mqtt connector for smallrye messaging dev ui (Quarkus 3)

[bulldog98]

Description

It would be nice to have a list of subscribed topics and topics to publish to. Also a way to get a debug UI for viewing messages going over the broker would help.

Implementation ideas

For the topics we could have items in the card like we have for beans in the arc extension.

For the messages debug page, I thought about starting MqttX (the web version) in a docker container and linking the page in the card, there is a container image for that from the vendor (docker.io/emqx/mqttx-web), but I'm not sure if the team wants that.

I'm also willing to contribute these improvements, but wanted feedback about the idea first.

[quarkus-bot[bot]]

/cc @Ladicek (smallrye), @jmartisk (smallrye), @phillip-kruger (smallrye), @radcortez (smallrye)

[phillip-kruger]

/cc @cescoffier