Class for the InMemoryTriggerStore. How the Logic App works, it will call the PUSH trigger endpoint with the triggerID and CallBackURL - it is the job of the API App to then call the CallbackURL when an event happens. I utilize this InMemoryTriggerStore to store the triggers I am watching, so that I don't continue to spin up new listeners whenever the Logic App asks me to register a trigger. If the API App was ever to reset or lose connection, I would know I need to register new Event Hub Listeners as the InMemoryTriggerStore would be empty.