Add light.move

[agoode]

Many light devices support a "start/stop" "raise/lower" command, which is used to smoothly change light levels based on physical remote press/release actions. This is important for two reasons:

• Sending start/stop commands minimizes radio transmissions while providing smooth dimming when controlled with buttons
• When lights are grouped, a move command will correctly change the light levels independently and by the same amount (all lights will change at the same rate for the same time, keeping their relative differences).

This kind of command is supported natively by Matter, Zigbee, Lutron, and probably others. (Hue has something close, but it doesn't quite work properly https://developers.meethue.com/forum/t/surprising-behavior-with-dimming-delta-on-grouped-light/7031).

In Matter and Zigbee, this is the Move command. Lutron calls it "Start Raising" and "Start Lowering" in the old integration protocol: https://assets.lutron.com/a/documents/040249.pdf. (There is probably a LEAP version, but it is undiscovered as yet.)

Right now, Home Assistant cannot implement this smooth level change. Workarounds exist: the behavior may be emulated by sending multiple small step commands, but these may exceed Zigbee's low multicast rate and does not work correctly with groups (home-assistant/core#118009).

I think there are a few related light improvements worth investigating, all somewhat related to exposing more of the underlying light's native functionality. This one (light.move), #537 (light.adjust), and also some better group handling. I'm not sure the best way to make progress on all these, but I will try to keep this one to a small scope.

[elupus]

Knx can be added to that list.

[InovelliUSA]

Have been wanting support for this for some time. To add to the conversation, Z-Wave also has this functionality via the MultiLevelSwitch command class. The commands are StartLevelChange (up or down) and StopLevelChange. It would be nice if all protocols that support this functionality (Matter, Z-Wave, Hue Bridge, Zigbee, etc.) could be supported which would allow for cross protocol integrations. Looks like Z-Wave JS supports this command currently.

[tringenbach]

The Bond integration has this feature or similar too https://github.com/home-assistant/core/blob/dev/homeassistant/components/bond/light.py#L196

But it's deprecated, and the button approach is awkward. And either way it's non-standard. As a user, I want this part of the generic light integration, so that my automations don't have to care what kind of light it is.

There is https://www.home-assistant.io/integrations/light/#action-lightturn_on transition already, which is close, but you have to specify how much you're increasing / decreasing ahead of time, and there's no "stop".