Fix: pass config and kwargs to passthrough_fn runnable for issue 665

[vpr1995]

fix: updated the code to pass config and kwargs to passthrough_fn

also wrapped synchronous runnable into asynchronous so that it stays consistent with all synchronous runnables

issue link

[vpr1995]

By wrapping the synchronous invoke in an async coroutine, I was able to run the runnables which only support synchronous implementation

[drazvan]

Thanks @vpr1995! This looks good 👍 .
Can you also add a test for this? Something basic, to make sure we don't break this in the future.
Also, please make sure your commits are signed. Check out the contributing guidelines: https://github.com/NVIDIA/NeMo-Guardrails/blob/main/CONTRIBUTING.md#submitting-your-work.

[drazvan]

Thanks!