Metricbeat doesn't include object labels and annotations on Kubernetes metricsets. As of today It's possible to enrich pod, container, state_pod and state_container events using add_kubernetes_metadata, but it would be nice to automatically add these fields to all object kinds, without the processor.

We should implement a metadata retrieval mechanism (or watcher) for all object kinds, and use a configuration similar to add_kubernetes_metadata to whitelist labels and annotations.

As a result, all kubernetes metricsets should include kubernetes.labels and kubernetes.annotations if the user wants them.