GET Monitoring: add kubernetes saturation metrics

Add kubernetes monitoring to GET similar to that used on GitLab.com.

This adds the following dashboards to the Service Overview for each service:

Service Overview Kubernetes Panels

Taken from https://dashboards.gitlab.net/d/web-main/web-overview?orgId=1

Kube Containers Dashboard (per service)

Taken from https://dashboards.gitlab.net/d/web-kube-containers/web-kube-containers-detail?from=now-6h%2Fm&to=now%2Fm&var-PROMETHEUS_DS=Global&var-environment=gprd&var-stage=main&orgId=1

Kube Deployment Dashboard (per service)

Taken from https://dashboards.gitlab.net/d/web-kube-deployments/web-kube-deployment-detail?from=now-6h%2Fm&to=now%2Fm&var-PROMETHEUS_DS=Global&var-environment=gprd&var-stage=main&orgId=1

cc @cmiskell @ccasella