CSharp - evaluate value of response handler parameter

[baywet]

We recently removed the response handler parameter from the Go API surface to reduce the size of the SDK which proved sucessful.
On top of filtering out the parameter in a refiner, we removed it from the request apdater API surface, updated the code generator method and added a new HandlerOption so people can pass it with the request options instead of via the API surface.
The scope of this issue is to evaluate (and eventually implement) such a change