Dev Service for MQTT broker

We can add a MQTT broker to the known dev services
https://github.com/apache/camel-karavan/blob/main/karavan-web/karavan-app/src/main/resources/services/devservices.yaml

This makes it easier to spin up a MQTT broker for development with karavan

There is an example here with a docker compose file we can use as inspiration
https://github.com/apache/camel-kamelets-examples/tree/main/jbang/mqtt

Start with karavan-web/karavan-app/src/main/resources/services/devservices.yaml and compare its existing service definitions with the docker-compose example in the linked camel-kamelets-examples MQTT directory. Add the MQTT broker to the known dev services so it can be spun up for Karavan development, then verify the service definition is recognized.

Written by the indexing model from the issue text.