(TK-20) Webrouting Service

This PR adds a new optional webrouting service that can replace a project's dependency on the Jetty9 webservice. It offers the same functionality as the webservice, but allows the user to specify the endpoints they want specific services to register in their configuration file and add them by passing in the namespaced symbol of a service rather than directly passing in an endpoint.
No, I mean a separate repo.  Because this service has a generic dependency on a :WebserverService; it isn't theoretically coupled with any specific implementation of that protocol, so it doesn't really make sense to have it so tightly coupled with the specific jetty9 implementation and live in the same repo.

I also don't think it should replace the current signatures of the webserver service because I think there are still use cases for them.

All of that said, since we don't actually have any other implementations of the webserver service to date, and I don't forsee us having any any time real soon, I'm inclined to favor simplicity over my idealogical purity and say that this can live here for now, and may need to be extracted some time in The Future.