Separate `adwaita-icon-theme` icons from general icons
One thing I've noticed when using Icon Library is that it will show icons installed by other apps on the host. App developers may think they can simply rely on them being there, but that's not really the case. Ideally there should be some sort of separation between the icons that we know are part of the platform, and the icons that come in random apps. Not sure how feasible this is.