A simple language for describing whether a label
exists and whether the value corresponding to it is in some set.
Intended to correspond to the capabilities offered by Kubernetes label selectors,
but without directly exposing Kubernetes API code to consumers of this module.
Get the recommended Kubernetes labels (app.kubernetes.io/*)
WARNING: this is duplicated in src/orchestratord/src/k8s.rs and src/cloud-resources/src/crd.rs