Tidy up the interfaces
Created by: tsodring
The interfaces have evolved to be a bit of a mess at the moment. It's because our understanding of the Noark 5v4 interface standard has evolved and it has become clear that the secondary Noark entites will also require systemIds. Some (perhaps all) interfaces for secondary entities are really redundant. There probably still is a need for a seperate INoarkSystemId entity. It's not a big job really, but requires some thinking to make sure it's done correctly and allows the code to evolve nicely.