cluster data collection: add defensive checks to collection implementation

e.g., when we iterate over Daemon Sets, we scoop up the version thusly:

`Version: daemonSet.Annotations[versionAnnotation],`

In the event that a Daemon Set (or other k8s resource) has been installed without our expected annotation key, we should log a warning.

Additionally, `Image: &rc.Spec.Template.Spec.Containers[0].Image,` assignment in the same routine would benefit from checking for the unexpected case when the `Containers` slice is empty.