Add library to simplify using Owin pipeline in ASP.NET

[twsouthwick]

For example: https://github.com/danroth27/AspNetWebApiCore/blob/main/OwinApplicationBuilderExtensions.cs

Related issue: dotnet/AspNetCore.Docs#25664

[adityamandaleeka]

Triage: might consider wrapping the Builder API to make this easier/simpler.

We'll probably want to put it in a separate library (to minimize unnecessary dependencies in S.W.Adapters).

[davidfowl]

I wrote a sample here https://github.com/davidfowl/AspNetCoreOwinSample