Connect to second sensor board for new thermal tests.

The next thermal tests will have/require additional temperature probes, more than can be connected to the existing sensor board. By far the easiest way (for me) to add more is to add a second board, controlled either by the xcuActor or the idgActor. TBD (umm, xcuActor already has the temps controller code, but the idgActor can generate local actorkeys more easily).