- Add user_auth_by_provider metric definition
  as object with related json schema
  - Remove individual metrics definitions for
  user_auth_by_provider
  - This fixes user_auth_by_provider, topology
  and projects_with_enabled_alert_integrations_histogram.
  This metrics are now added to service ping payload.
  - Add tests for object metrics
  - A hash could be a metric, with this MR
  we change th meaning of a leaf in payload.
  - A metric is a leaf if it has a metric defintion

Changelog: fixed