Supports commands for on/off, brighten/dim, colder/warmer and night.
Start with a configuration for an Iris Ohyama light.

Total steps is 10 (5 in each direction from "centre"), not 5.

- Save the previous value in closest_match so we can judge whether it was
  closer than the higher value.
- There are various cases where we support brightness, so use a separate variable to track that
- Add some debug logging to changes
- Don't fallback to the "on" command when we got a brightness or color temperature but decided it was the same step we are on, so didn't do anything.

The remote has "Full" (full brightness, mid color temp), "Night" (nightlight)
and "Memory recall" buttons for turning on, and a "Memory set" button for
saving the current brightness and color temp in memory.

- Use the "Memory save" before the "off" command to save as we turn off.
- Use "Memory recall" rather than "Full" for turning on.

When using this with Adaptive lighting, during the day the light keeps beeping due to reaching the end of its range every 90s.
This is because Adaptive lighting is trying to adjust the brightness and color temperature, but they are not actually moving because of the limited number of steps.
Putting the resync code inside the condition that we actually need to move the brightness should prevent this, and only resync when we are actually changing to the end of the range.