Enable https for web interface

[camueller]

Google Chrome is more and more entforcing https - we should run on https as well.

https://www.thomasvitale.com/https-spring-boot-ssl-certificate/
https://www.baeldung.com/spring-boot-https-self-signed-certificate

[starwarsfan]

That's great but it should not be enforced in general because if a reverse proxy is used to terminate https, the traffic from the proxy to the application within the local network could still use http. You can do that with https of course but if it's a requirement to use https within the local network, you might have other issues... ;-)