Unify patch system

[nightkr]

Currently, each product has its own copy of our overall patch system. It would be nice to unify them into one implementation in one location that all of them can reference.

[lfrancke]

I'm not sure how much we want this issue to spiral out of control but we can also use this to discuss how we want to handle patches and build-from-source in the first place.

We can also fork the upstream repos and build the things including patches there once, push them to a registry and only fetch them from there during image build....