SDK: consider to add start method on Tracer with config param

[mayurkale22]

Originates from #118 (comment)

This method will help us to pass config params on to the tracer. Currently, the BasicTracerConfig is defined at the constructor.

[dyladan]

@mayurkale22 @draffensperger is this still a relevant issue? Looks like this comes from the TracerDelegate which is gone now.

[draffensperger]

I would say feel free to mark this as closed. If we have a need for the underlying issue with the new architecture, it will resurface at some point.