FreeIPA/LDAP integration

I'd like to request FreeIPA and LDAP integration as a means of authentication on GitArena. Integration for this exists on other self-hosted git instances such as [Gitea](https://docs.gitea.io/en-us/authentication/), [GitLab](https://docs.gitlab.com/ee/administration/auth/ldap/) and would likely be a used feature on GitArena.