Add new RPC call to update submodule ref in repository
Adds a new RPC to allow updating the submodule's ref in a repository through the API.
This call needs the repository, the submodule name, the ref to update to, the branch, the user and the commit message.
Refs: https://gitlab.com/gitlab-org/gitlab-ce/issues/41213 and gitaly!936 (merged)
Edited by Francisco Javier López (ex-Gitlab)