This will make it possible for us to render their avatars. Previously we only had the user ids. During rendering, everything needs to be available synchronously. So now, whenever collaborators are added, we perform the async I/O to fetch their user data prior to adding them to the worktree.
This will allow us to use the word "collaborator" to describe users that are actively collaborating on a worktree.
Co-Authored-By: Antonio Scandurra <me@as-cii.com>
