- this was an experiment to casually monitor sensor offsets relative to temperature, but now that all calibration offsets can be adjusted post-flight the stored temperature can be misleading
- deleting to save a little bit of flash (and storing the temperature wasn't useful)
- centralize logic for selecting a preferred calibration slot
- automatically use existing calibration slot if it exists, otherwise
find first available slot, with a preference for a requested index
- existing commander calibration methods rewrite all calibration slots
to match current sensor ordering