Part of epic: https://gitlab.com/groups/gitlab-org/-/epics/9692 After https://gitlab.com/gitlab-org/gitlab/-/issues/388918 is completed. ### Problem https://gitlab.com/gitlab-org/gitlab/-/issues/388918 introduced a new field (LoC count) in CommitLanguages RPC. We need to return this data via API. ### Proposal * Extend [Project Languages API](https://docs.gitlab.com/ee/api/projects.html#languages) to return LoC info