(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.
Seems like there's some opportunity to DRY up these 5 functions significantly.  `svc`, `route-id`, `path`, and `opts` are the same across all of them; I'd probably introduce a new function compute those things for you in one shot ...
```clj
let [{:keys [svc route-id path opts]} (compute-common-stuff context svc options)
     ...
```