Issue description

These two files are really similar and can hopefully be refactored to reuse the same code. installation-cd-graphical-base.nix was added in #46510 by @worldofpeace. hopefully i understand its use case and we can make it more generic to apply in the virtualbox appliances.

See discussion in #47204

So I think there is some confusion here because profiles/graphical.nix & installer/cd-dvd/installation-cd-graphical-base.nix do almost the exact same thing. The main difference is one is going into the .iso and the other into the .ova. It seems like we should refactor to avoid duplication here.