This is somewhat in the works.
There is an issue on GitLab to enable federated pull requests and I believe Gogs/Gitea community is working on getting some sort of standard figured out if I'm not mistaken.
Issue for reference https://gitlab.com/gitlab-org/gitlab-ce/issues/4013
Perhaps we should build something like gnu social (or diaspora, but not as bad) for code projects, or build on existing distributed social networks.