Document how to use OWIN IAppBuilder based frameworks with ASP.NET Core

ASP.NET Core supports an OWIN bridge, but many OWIN based frameworks shipped by Microsoft (like ASP.NET Web API) rely on the OWIN IAppBuilder, which this topic doesn't document how to integrate with.

We should document the required code, which looks something like this (but updated to use supported APIs): https://stackoverflow.com/a/30791150/3294414.

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#### Document Details

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* ID: 34916983-6cf6-590e-0762-df0fe4e4f52c
* Version Independent ID: 1bf5bce0-c571-296e-1e8a-896af7068499
* Content: [Open Web Interface for .NET (OWIN) with ASP.NET Core](https://docs.microsoft.com/en-us/aspnet/core/fundamentals/owin?view=aspnetcore-6.0)
* Content Source: [aspnetcore/fundamentals/owin.md](https://github.com/dotnet/AspNetCore.Docs/blob/main/aspnetcore/fundamentals/owin.md)
* Product: **aspnet-core**
* Technology: **aspnetcore-fundamentals**
* GitHub Login: @ardalis
* Microsoft Alias: **riande**