Add selectable AUX to indicate current channel on multichannel lights

[dirtymoustache]

Proposing a feature to select specific aux colors to indicate which channel is currently selected on a dual or triple channel light.

This could be useful, and a nice safety feature. In particular, when lights have a UV channel, it can be difficult to discern if UV is on when a white light is on, but separate AUX colors would make this obvious.

Using this feature, a user could configure a light as such

Example: D4K Triple channel light with CH1 as white, CH2 as red, and CH3 as UV

Mode	AUX Color
CH1	White
CH2	Red
CH3	Blue
CH1 & CH3	Cyan
CH2 & CH3	Purple

A UI could be created as such

• 8H: Aux extras config menu.

  Item 1: Synchronized AUX on all channels Item 2: Separate AUX per channel

A user selects item 2. They enter a channel, set the AUX color, and it assigns to only that channel. A user selects item 1. All channel AUX colors are set to what Channel 1 is currently and AUX returns to normal operation.

[fiveseven808]

Just a quick question because I didn't want to buy a 3ch d4k until I completely understood how the channels could be configured, the above values in the table are the only possible channel mixes? I.e. is there no CH1 & CH3 mode?

[SiteRelEnby]

At the moment, on the most common wiring config, main+4th channel is not available for ramping, the other mixes are.

I added the missing mix in this PR: https://github.com/ToyKeeper/anduril/pull/36