Handle and return errors in internal/config/

What does this MR do?

Handle and return errors in internal/config/

Closes #550 (closed)

TODO

• Added the Changelog (e.g. Changelog: feature) trailer to the commits that need to be included in the changelog
• Added unit tests (if required)
• Added acceptance tests (if required)
• Documentation (if required)
• Code review guidelines
• Go Style guidelines