Provision Grafana configuration via Terraform
Using the [Grafana provider](https://registry.terraform.io/providers/grafana/grafana/latest/docs), we can use Terraform to provision:
- dashboards
- folders
- datasources
- teams
And we can also leverage the [Jsonnet provider](https://registry.terraform.io/providers/alxrem/jsonnet/latest/docs).
It would make:
- dashboards provisioning way faster and easier to cleanup (currently done with a script synchronizing one by one very slowly)
- folders less hidden (currently created manually by that same sync script and slow)
- datasources easier than done currently in `tanka-deployments` and with better secret management
- teams no longer manual and more visible
Which repository should it be managed in?
- [config-mgmt](https://ops.gitlab.net/gitlab-com/gl-infra/config-mgmt)
- [runbooks](https://gitlab.com/gitlab-com/runbooks)
- its own separate repository for everything Grafana
issue