feat: kubernetes dashboards for the monitoring service

• Requires !4362 (merged)

First pass at adding some kubernetes dashboards for the monitoring service:

1. Containers: https://dashboards.gitlab.net/dashboard/snapshot/P5UcAY5Ri7EV0FcoBLkTIBbHEJEJgGSZ?orgId=1&var-PROMETHEUS_DS=Global&var-environment=ops&var-stage=main
2. Deployments: https://dashboards.gitlab.net/dashboard/snapshot/jw8CeXZcTf8U8kMrR5P5r2kpo1X00iqx?orgId=1&var-PROMETHEUS_DS=Global&var-environment=ops&var-stage=main