Create AsyncTaskCompletionSource

[Haydabase]

When awaiting TaskCompletionSource.Task the continuation after the await can be executed on the calling thread (e.g. the caller of SetResult) synchronously if the Task is not completed when originally awaited.
This is undesirable in many case, for example if the calling thread is a thread dedicated to polling for instance, since the thread is then prevented from continuing it's dedicated work.
A version of the class which ensures continuations of the underlying Task are always executed on a different thread is desired.