Wait for service calls to complete concurrently

[Skehmatics]

In some configurations, a light's service call may take a moment to complete (50-500 ms). This is acceptable when controlling a single device, however if the lightener group is more than a handful of devices changing states can take multiple seconds!

To improve the experience when this is the case, this change makes each call a task and awaits them as a group before unlocking the lightener device. This improves the time it takes my rooms' lights to settle on the desired state from ~5 seconds to ~100ms.