Add periodic Geo health checks to geo-logcursor

• Add Geo health checks to geo-logcursor health checks https://gitlab.com/gitlab-org/gitlab-ee/issues/14627
• If possible during refactoring, make it easy to add Geo health checks to the health check endpoints: https://docs.gitlab.com/ee/user/admin_area/monitoring/health_check.html. Note that the existing Gitlab::Geo::HealthCheck is used in rake gitlab:geo:check as well as the HealthCheck initializer.