Fix loading of environment variables

[ccremer]

Summary

• Removes Go dependency to koanf
• It's not really worth having a 3rd party lib for 4 settings, when only env vars are used.
• Actually fixes loading of environment variables, and displays them at startup.

Replaces #121

Checklist

For Code changes

• Categorize the PR by setting a good title and adding one of the labels:
  kind:bug, kind:enhancement, kind:documentation, kind:change, kind:breaking, kind:dependency
  as they show up in the changelog
• PR contains the label area:provisioner
• Link this PR to related issues
• I have not made any changes in the charts/ directory.