Add Async Support on the CosumeOf Interface

[kdcllc]

I would like to see support for the async and await pattern thru the layers up to ConsumOf interface and its implementation. I am running with such in with one of my client.

[trailmax]

That is a fine idea and I think I looked into that initially, but I have not implemented it because it involved significant amount of work. I remember I have tried it but got blocked by some of the async api and could not resolve that in short enough time, so I dropped it.

In principle, yes, it'll be great. In practice I'm very busy just now and no time to implement it in any forceible future.

[trailmax]

@kdcllc I had a quick-stub at async functionality - available in async branch. Unfortunately async turtles all the way down. See this test. A lot of issues here:

• A lot of breaking changes - need async methods on interfaces ISagaMediator, ISagaFactory.
• Most likely will need IAsyncSagaMessage and IAsyncInitiatingSagaMessage to be sure the correct method is called with appropriate await
• Possible wad of other changes that I don't see just now.

Basically will have to rewrite the whole thing from scratch and double the public API surface. As I suspected before this is a lot of work and time that I don't have just now.

[kdcllc]

@trailmax, That what I thought. I do not have time at the moment as well, so I have wrap the code in the async tasks for now. Thanks!