Contributes to https://gitlab.com/gitlab-org/gitlab/-/issues/334140

Follow-up for
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/66657

**Problem**

Gitaly GetTreeEntries RPC supports pagination. But Rugged
implementation for it is missing.

**Solution**

Reimplement Go
version (https://gitlab.com/gitlab-org/gitaly/-/merge_requests/3611)
in Ruby.

Changelog: added