There's not really any analogous concept for azimuth. This is for a
specific piece of hardware, so there's no real point in making it more
generic. This is respected at the 180 degree point as well, for
software that can handle flipped rotation configurations.
This doesn't currently play well with the elevation offset setting,
which should be applied after this clamping operation. Either this
needs to be moved to the API layer or (more appropriately) the input
range validation needs to move in the controller.
This is missing a little bit of input validation, e.g. we don't
currently check that set_position azimuth and elevation are actually
in the range that the controller can possibly move.
The geodetic north offset configuration value is applied in when
computing the current position, but I think there are still some
slightly fiddly edge cases around it and I haven't actually figured
out which direction I want the sign to be.
The various pieces appear to be functional, so next up will be figuring
out what all the problems are with some hardware in the loop.
