API: Add upward inheritance.

Currently inherited permissions are not expanded if the inherited group has more permissions to a lower level group. This will be confusing for users.

TODO:

[ ] Add tests to test inherited permissions (downstream and upstream)
[ ] Automatically emit updated accessMaps to clients when updated in the API permission system (separate issue?)
[ ] Create issue: Super Admin user able to remove his own edit access

bccsa / luminary

API: Add upward inheritance. #261