* [nanoleaf] More color for less network calls
This is a refactoring that moves the "get panel color" out of the
panel handler and into a separate class, with callbacks.
This makes us do only one REST call to get colors instead of one per
panel that is a thing. It also lets us retrieve colors for all panels -
also those that doesn't have a thing in OpenHAB,
While testing this out, I found a bug where solid colors set in the app
wasn't reflected in neither the controller nor panel channels, and that
should also be fixed now.
Signed-off-by: Jørgen Austvik <jaustvik@acm.org>
70cca8fc77