Allow OpenShift users to configure audit logs for prometheus-adapter

After investigating a complex Bugzilla involving many applications making queries to prometheus-adapter, we've noticed that we were lacking insights on the requests made to prometheus-adapter. To have such information for an aggregated API, the best would be to have audit logs for prometheus-adapter. This wasn't configurable before, but with https://github.com/kubernetes-sigs/custom-metrics-apiserver/pull/92, upstream users should now be able to configure it.

Since this would greatly help in investigating prometheus-adapter Bugzilla in the future, it would be great if we allowed OpenShift users to configure the audit logs so that they could provide them to us.

Note for the assignee: as of the time of the creation of this ticket, the upstream PR hasn't been merged in custom-metrics-apiserver and thus wasn't synced in prometheus-adapter. So we will have to wait a bit before starting looking into this ticket.

DoD:

• Allow OpenShift users to configure audit logs for prometheus-adapter
• Integrate with must-gather
• Document how to configure audit logs in the official OpenShift documentation
• Upstream jsonnet patch that enables this feature through a configuration