Gateway device to network

It would be advantageous if not every device had to be connected to the onboarding server, assuming they did not need the SZTP functionality. This would allow us to manage devices that are not directly connected, which would also have the side effect of reducing the number of connections the onboarding server needs to manage.

There is a proposal in AW+-land to support this on the wiki. It has not yet been scheduled, but it has had a brief review by the AW+ Arch group.