Integrate with rotator control (rotctld)

[xylo04]

Some stations have antennas that can be rotated. Usually this is just azimuth, but some stations (especially for satellite work) include rotation for elevation. This would be a great addition to automatically record in QSOs.

This mostly requires work in k0swe/kel-agent#88. After that, plumbing the new messages through https://github.com/k0swe/ngx-kel-agent and into Forester will be straightforward.