[DCR] Strongly Type CreateOrchestrationInstanceAsync

I think it'd be a good exercise to see what it would take to change our `object` overloads to generic ones so we can more strongly-type the developer experience instead of having to rely on boxing/unboxing.

In Durable Functions, we're [now strongly-typing our calls to `StartNewAsync`](https://github.com/Azure/azure-functions-durable-extension/commit/8446057cee423b9b652e3e34e99ca73fd45415a6) which hits these APIs underneath, but unfortunately this still results in boxing/unboxing and [forces us to take reference types](https://github.com/Azure/azure-functions-durable-extension/blob/master/src/WebJobs.Extensions.DurableTask/ContextInterfaces/DurableContextExtensions.cs#L430) vs accepting all types (e.g. `int`) which [has caused some confusion for developers](https://github.com/Azure/azure-functions-durable-extension/issues/1056)