Change scene update logic to use new scene api

[torandi]

API 1.29 introduced a way of updating all lights in a scene in one go. This PR changes the scene update logic to use that.

I haven't deleted the old SaveSceneLightState in this PR, as it could be use as a fallback if you desire to support the old api as well.

My main reason for this fix is that updating all lights in a large scene results in 500 or connection reset from the hub, as it get's too many requests in a short time.

[sqmk]

Right on. I'll check out the API changes and try to get Huejay in sync.