Export data sources to provisioning datasource.yml

### Discussed in https://github.com/grafana/grafana/discussions/68844 <div type='discussions-op-text'> ^{Originally posted by **kevinlinxc** May 22, 2023} The context is that I am running Grafana locally, either with the server executable or with Docker. Currently, I think you have to manually trial and error your `provisioning/datasources/datasource.yml` file until the datasource is correctly provisioned. However, it is much easier to iterate on the Grafana UI when adding a datasource, so why not make the datasources on the UI exportable to a yml file? Same goes for dashboards.</div>