[FEATURE] currentURL MQTT push

[starkillerOG]

Your feature request. Please describe.
What is the feature, why is it valuable to the community or application?

The current URL that is displayed in the app is published on the /state topic on MQTT inside the json message with key currentURL.
This is greath since it allows for some nice automations using HomeAssistant in combination with the {"url": "http://"} command.
However the current URL is only published every x seconds which is configurable in the WallPanel settings.

I would very much like the currentURL to be published to MQTT immediately on a change of the URL in the application.
This is already done for the motion and face detection topics, so I think it schould also be posible for the /state topic on URL changes.
This would allow for even nicer automations and more control using automations in HomeAssistant.

Thank you very much for the greath app, keep up the good work, much appriciated!

NOTE
We get many feature requests, each feature requires community support and also development time. Features that have no community support are not considered. If you are not contributing to the feature, then the feature may not happen.