Allow Pipeline environment variables to be created at the Team level

We have a lot of repositories which all build and deploy code in the same general way. It would be great to be able to create Pipeline environment variables at the Team level and then be able to share them or reference them in the individual projects.

The challenge without this feature is key rotation. We change our builder credentials (i.e. AWS keys) on a regular basis. So having to go update 20+ repos individually is a pain.