Add a kube-state-metrics integration

[ndrpnt]

Request

Transferring #474 from the now-deprecated Agent repository.

It would be nice to have kube-state-metrics integrated to Alloy.

kube-state-metrics (KSM) is a simple service that listens to the Kubernetes API server and generates metrics about the state of the objects.

Use case

It is a de facto standard for monitoring Kubernetes and comes bundled with kube-prometheus-stack (and the its helm chart). Common (bundled in kube-prometheus-stack) dashboards depend on metrics exported by KSM to work.

[marctc]

The original issue is moved here: #474

[ndrpnt]

Nice, closing this one then!