Method offers next element to a stream and returns task that:

- competes with QueueOfferResultEnqueued if element is consumed by a stream

- competes with QueueOfferResultDropped when stream dropped offered element

- competes with QueueOfferResultQueueClosed when stream is completed while task is active

- competes with QueueOfferResultFailure when failure to enqueue element from upstream

- fails if stream is completed or you cannot call offer in this moment because of implementation rules (like for backpressure mode and full buffer you need to wait for last offer call task completion.

Task<IQueueOfferResult> OfferAsync(
	T element
)

abstract OfferAsync : 
        element : 'T -> Task<IQueueOfferResult>