title: GCP quota and billing at user level
body: <p>I am trying to see if there is a way for me to bill and restrict users based on their usage of resources across projects on our GCP instance.  I know billing and quotas officially are at the project level, but we will have shared projects which will be used by people in seperate cost codes.  I was thinking of building an API per cost code, and having people access the resources only through there, but I'm not sure if this is the best idea.</p>