Build a module for river pod annotations discovery

We currently provide in helm a configurations that allows to activate scraping per pods using annotations

see https://grafana.com/docs/pyroscope/latest/deploy-kubernetes/helm/#optional-scrape-your-own-workloads-profiles

I suggest we make this configuration https://github.com/grafana/pyroscope/blob/main/operations/pyroscope/helm/pyroscope/templates/configmap-agent.yaml

a module that can be imported. https://github.com/grafana/agent-modules/