recover-broker-info should be able to use secrets

[skitt]

subctl recover-broker-info relies on the CA and token stored in either the Submariner or ServiceDiscovery objects. Since we want to stop storing these, we should try to find a way to make it work using only secrets. This might not be possible directly, in which case we might need to go through an in-cluster pod: in the cluster we have access to, start a pod, mount the secrets there, and use that to access the broker.

[stale]

This issue has been automatically marked as stale because it has not had activity for 60 days. It will be closed if no further activity occurs. Please make a comment if this issue/pr is still valid. Thank you for your contributions.

[github-actions]

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.