Interceptor wms reflector option for interceptor

[ahennr]

This PR introduces an option for GeoServer interceptor (parameter useReflect) to call WMS reflector endpoint of GeoServer.

An example call to interceptor (layer dumpy in namespace humpty) would be:

http://localhost:9090/geoserver.action?layers=humpty:dumpy&useReflect=true

[buehner]

LGTM 👍
very nice addition

[ahennr]

THX for review @buehner

[marcjansen]

I think this breaks backwards compatibility by effectively removing the previously public method URI getGeoServerBaseURIFromNameSpace(String geoServerNamespace).

I think this should have at least deserved a release.