Multilevel device control in scenes

This feature is quite crucial indeed, and quite simple to develop, so I moved its development forward despite it having few votes :smiley:

I worked on it yesterday afternoon and this morning:

Control of a multilevel device

Control of a color device

Control of a lamp temperature

Control of a binary device

Actually, the goal of this new action is to be able to control absolutely all types of devices in the scenes. Yes, it is redundant with the « turn lights on/off » or « turn outlets on/off » actions, but these two actions are, in my opinion, « shortcuts » to go faster and turn on several lamps at once :slight_smile:

The PR is here: