.Net: Concept sample showing how to terminate and return function call result

[markwallace-microsoft]

We have existing samples which show the mechanics of this but they also include other concepts.
The goal for this task is to create a very focussed sample that should work as follows:

• Register two functions both of which we expect to be called in a particular sequence e.g. one could retrieve context and the second could perform an action
• Trigger termination when the second function is called and use that functions result as the response