Make the Grafana module more flexible so it can be re-used
Back-porting recent changes from the following PRs in LeastAuthority/infrastructure:
- Configure new monitoring with Grafana only re-using PSio module #311
- Enable anonymous viewer authentication by default for Grafana #313
- Ensure anonymous access is configured explicitly #316
The goal is to make the module flexible enough to be used in both projects by only passing different values for a few more options.
Edited by Benoit Donneaux