Provide an API that returns a detailed list of changes that have happened in a repository. This includes new artifacts getting added to the repo and any tag updates that happen. See https://docs.google.com/document/d/1i-HGSHqazVq8cEqeLNqAZtmacPjT625MezsNU94eGHc/edit#heading=h.onhumro9gtic for details.