Improve Config on k8s

[tomas-langer]

Investigate options for improving config location pick-up on a Kubernetes pod.
Is there a way to discover config maps/secrets? If so, can we easily add it as config sources to Helidon?

If such a discovery is possible, we could add a simple switch (config option, env var, sys property) to enable such automated pickup (+ having a module on classpath).

This would simplify deployment to k8s.
The current way is to use Helidon SE profiles, or Helidon MP meta conifguration with optional locations for the files to be loaded.