Use recommended Gitaly Cluster config
This replaces the existing Praefect scenario config with one consistent with the minimum recommended configuration.
- Rename GitalyHA to GitalyCluster
- Refactor GitalyCluster class to reduce nesting
- Complete configuration
- Add Gitaly Cluster scenario jobs
Closes https://gitlab.com/gitlab-org/quality/testcases/-/issues/767
Depends on: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/35572
Edited by George Koltsov