Use Gitaly to handle reference checks

What does this MR do and why?

Contributes to https://gitlab.com/gitlab-org/gitlab/-/issues/556674

Problem

Currently GitLab relies on the Redis cache to identify the presence of branches and tags in the repository. Maintaining this cache is expensive for large projects.

Solution

Trigger a ListRefs call to Gitaly to load all necessary branches/tags per project. Use results of this call for branch/tag presence checks.

References

https://gitlab.com/gitlab-org/gitlab/-/issues/556674+

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #556674