Show the selected light control on light group members (#54167)

* Show the selected light control on light group members

When a light group's more-info dialog is switched to color temperature, the
member tiles listed below now show a color temperature slider instead of
brightness, so the children can be adjusted on the same axis as the group.

The light control fires light-main-control-changed whenever its main control
changes, and more-info-content picks the member tile feature from that.
Members that do not support color temperature keep their brightness slider,
and the color mode keeps brightness since there is no tile feature for it.
Legacy group.* entities are unchanged.

* Hide member light control when group is in RGB color mode

There is no RGB tile feature, so showing a brightness slider on group
members while the group control is set to color is inconsistent. Show no
control in that case instead, per review feedback.