Extend authentication with external authorization source
as last (if WMS cascading is descoped) requirement to complete for evolutions?
more info on the external service endpoint still to be provided by TPZ
this issue means completely removing shibauth service and configuring traefik forward-auth middleware to this external service & check if we provide enough info to the external service to make the decision (might need splitting of download & rendering requests - split renderer to (downloaded + renderer)