Add config API for kuberc v1beta1

[soltysh]

/assign @tengqm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: soltysh
Once this PR has been reviewed and has the lgtm label, please assign jimangel for approval. For more information see the Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[tengqm]

@soltysh Thanks for the PR.
I'm wondering if we can/shall postpone this change until 1.34 is out?
The tradition was that we update go.mod when a new release is out.
The reason is that we cannot afford to manage all those *-alpha.* dependencies.