Implement boresight commands for SAT

[kmharrington]

Adding to the list of things: I have noticed that boresight positions aren't in the "move to" command.

EDIT: Co-rotator feature request split to #76.

[BrianJKoopman]

These will also need to be different for the LAT and SAT.

Thanks, Katie. How do these differ between the platforms? The ACU agent is common and has a single set_boresight() command, which I think might control the 3rd axis in either case.

[kmharrington]

Oh interesting that the commands are the same. Optically they'll be fairly different since the co-rotator isn't exactly a boresight rotation. I would imagine for the LAT we'd want functions that did move_to(az, el, corotate=True) and then an option to move the co-rotator independently. For the SAT the boresight really is a third axis and the use-case is more move_to(az, el, bore)