[che-auth] Chectl Setup Che7 with Dex instead of Keycaloak as OIDC provider for minikube

[skabashnyuk]

Is your task related to a problem? Please describe.

We would like to find a light way alternative to Keycaloak in the future.
Potentially Che7 and Devworspaces should use that alternative to work
together at the same time

Describe the solution you'd like

Chectl should be able to reconfigure minikube to use Dex as oidc provider

Here are the scripts from our research that setup Minukube with Dex https://github.com/che-incubator/che-auth-playground/tree/master/minikube_dex

Describe alternatives you've considered

n/a

Additional context

epic: Authentication and authorization in Eclipse Che #19182