Update ripple-topology-ui to use SpringBoot + Spring v5

[sappenin]

Currently, the ripple-topology-ui relies upon Server and SpringServer. Since this is an open-source project, we should probably use SpringBoot instead, and bump to version 5.

[manthanhd]

Strategically we should de-couple the server implementation from the server spec. We can do this de-coupling at the moment using maven submodules but eventually it would be good to take it out completely into its own open source project.

The main motivation being enterprise users can implement either their own server with infinite flexibility and it'll make testing almost implementation agnostic because we'll be testing the spec more thoroughly than the implementation.

@sappenin @MatthewPhinney - Thoughts?

[MatthewPhinney]

Yeah, I agree. In fact, I had removed the server from the closed-source topology library. I had placed it in its own repository (which was an HTTP server based application that utilized the topology library). I think Jimmie added it back here for completeness. Going forward I'd like to decouple the two, and, yes, a server spec is a good idea 👍

[manthanhd]

Fantastic! Assigning it to you @MatthewPhinney for now since you've done the removal of server piece before. Maybe later we can work together to extract the server spec.