Release grafana support

Created by: daniel-hutao

I found 【# - { path: prometheus/grafana, file: grafana-deployment.yaml }】 at 【roles/ks-monitor/tasks/generate_manifests.yaml:46】 when I try to use grafana to add a custom monitoring dashboards. The enabling of grafana was previously configurable by cc.spec.monitoring.grafana.enabled=true. I think release this comment will make ks more flexible, so that users who need to use grafana can optionally integrate grafana and which is not enabled by default.