Consider improving Kubernetes labeling for environment-scoped resources

[rynowak]

When we have an environment-scoped resource (eg: Applications.Connector/daprPubSubBroker) at environment scope, we generate labels like the following in Kubernetes:

      app.kubernetes.io/managed-by: radius-rp
      app.kubernetes.io/name: pubsub
      app.kubernetes.io/part-of: ""
      radius.dev/application: ""
      radius.dev/resource: pubsub

The application is blank for this case, so we end up with a blank radius.dev/application and a blank app.kubernetes.io/part-of.

I don't think that we've reviewed this behavior when we added environment-scoped resources, it's just a consequence of having a blank application field.

We have some options here:

• Current behavior is OK, leave it alone.
• Omit empty labels (this might not work due to the role of labels in matching)
• Add an additional label for environment-scoped resources radius.dev/environment-scoped: true

AB#6964

[emily-potyraj]

triage note: proposed for v0.13