Genode implementation templates

[jklmnn]

I noticed that when implementing interfaces on Genode there is a large part of duplicated code. It might be feasible to make parts of this code generic and provide it via templates. While this seems to be redundant to Genodes templates it still important to keep the actual objects simple (aka consisting of only basic types) so the template instances can be bound to Ada.
This approach needs to be evaluated first.