Consider renaming LightblueRequester to AsyncLightblueClient; move to lightblue client library

[alechenninger]

The interface and the bulk implementation are general purpose enough that it should probably be shared with all client library users.

[dcrissman]

I am not sure that I understand the rename suggestion as the LightblueRequester is not a descendent of LightblueClient, which I think would be confusing.

[alechenninger]

Not a descendant, but it's still a lightblue client logically speaking. There are many libraries that have a [Something]Client and an Async[Something]Client for the same service (for example Apache Thrift or gRPC code gen, I've seen it elsewhere too). They are just two different interface styles–sync vs async–to the same thing.