You can already do that in the Notifications panel (which you kinda pointed out in your next comment).
I think a better way of thinking about is that you can set the permissions (or features) from both an app page and from a permission page. In other words, on the Cheese page you would have on/off switches for Camera, Notifications, and some sort of file access to at least the Pictures folder. On the Camera page, you would have on/off switches for Cheese, Chromium, Firefox, Settings (to set your user profile). There are some mockups and discussion linked to or included in the Github issue mentioned in the first post here.
This is still a work-in-progress and more development, design and reworking is needed. I don’t know if this will be ready for GNOME 3.32 or not.