Returning a Deferred<Result<T>> from a Coroutine Async method

[mtimmerm]

@jadent

I think the reason this method was implemented as returning a Deferred instead was for the case where there was already an existing request for the same item and we can therefore just return the existing Deferred object that could again be waited upon using the await() method.

I’ve done the same thing many times for the same reason, but I would return, say Deferred<File> instead of Deferred<Result<File>>, and then catch around the await.