Move ReportingLib and Sonata Reports interface outside CoreNEURON

[pramodk]

Few years ago we added reportinglib interface in CoreNEURON due to immediate deadline and feature requirement for BBP simulations.

• As these features are BBP library specific, similar to NEURODAMUS, these interfaces should be moved to MOD file rather than a C++ code in CoreNEURON.
• If we see there is a value to have SONATA interface in CoreNEURON, we need to evaluate how this will be used by other users (e.g. through CoreNEURON) and modularise interface better.