Support --apiserver-host and --apiserver-skip-tls-verify in Auth module

[leonjyq]

What would you like to be added?

For the dashboard auth module, I would like to be able to specify the --apiserver-host and --apiserver-skip-tls-verify like what we can do in API module.

Why is this needed?

Below is the solution we want to implement, we specify the api host to kube-oidc-proxy to leverage its capability for impersonating the request with Azure AD group. API module supports specifying the api host, but Auth module can't. This causes that Auth module will talk to Kubernetes API server directly instead of kube-oidc-proxy, and Kubernetes API server doesn't acknowledge the token signed by Dex.