Add async IO support

[YohDeadfall]

To improve an overall performance of an app it makes sense to use async IO since it's not blocking and allows to process data in background and prevent the pooled thread from being blocked. The only blocker here is that BinaryReader has no async methods and all logic should be rewritten, but to avoid repeating internals and bringing errors to the existing code there is System.IO.Pipelines.

[roji]

Tracking issue in the .NET BCL for making BinaryReader async: dotnet/runtime#17229