allow for initial_layout in to_braket

[sesmart]

What is the expected behavior?

Initial layout is a common transpiler keyword, particularly for lower level optimizations. Currently we are verbatim or bust - if verbatim is provided, no transpilation occurs, but if it is not, any valid information on the circuit is lost. This is relevant for lower optimization_level = 0 | 1 cases.

[sesmart]

Or maybe we can just pass through transpiler options - that would be a bit more flexible.