Geo - Improve the performance of slow count queries triggered by the Geo::MetricsUpdateWorker

Implementation Guide

The Geo::MetricsUpdateWorker can trigger very slow queries to update the Geo node status and Prometheus metrics. In #370158 (closed), we used the Gitlab::Database::BatchCount to improve the slow total replicable count. So, to avoid having performance problems on large GitLab instances, we should change the other (*)_count methods to use the same approach.