feat(cli): order flags by categories (#1168)
feat(cli): order flags by categories (#1168)

We have many flags of the form `<category>.<name>`. This change orders them
groups flags by category.

All flags with no categories and all categories with a single flag only won't be
grouped and will be printed at the top
grafana/loki,grafana/loki,grafana/loki,grafana/loki,grafana/loki,grafana/loki