Cleanup some unused configurations

[lucasmdrs]

As previously discussed here, there are some configurations in controller and proxy package that are not required anywhere in the code and should be removed.

Remove MasterURL, KubeConfig and any other configuration that might be duplicated, unused or only used by the cmd package

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.