Add unique_id generation to Flux_led integration

The official Flux_led integration does not generate unique ids for the devices causing the following message:
“This entity (“light.front”) does not have a unique ID, therefore its settings cannot be managed from the UI. See the documentation for more detail.”
This restricts functionality, for example they cannot be added to Areas, nor managed in the UI.

So please add this to the integration so that it follows the standard. Thanks