Add capability to use sub-domains instead of paths to route traffic to PieDatas

Currently everything is behind the main KubePie root URL and only http path is used to route http traffic towards different PieData services.

Some use-cases, like s3, are not compatible natively with sub-path location.

The idea is to implement creation of Ingress with service-specified hostname that will further routed to PieData Pod and within PieData's reverse proxy config handled as well.

Same way we might want for a configurable option to change the behavior for the main PieData URL in KubePie to be created per-user (e.g. _{.) instead of per-user path prefixes.}