Use space labels to attach policies

Currently, we can only attach a policy to stacks directly, either manually or through autoattach labels. It would be great if the autoattach feature also applied to space level labels, for all of their stacks.

To explain our use case, we have a standard approval policy (on the root space) that we only want to apply to our production environment spaces, which are at the lowest level in our hierarchy. The only way for us to do this currently is to add a “prod” label to every stack under these spaces, which can be dangerous in case developers forget to add them. If we could just add that “prod” label to the production spaces, it would ensure that our policy always applies to all of their stacks.