Consumes the new APIs from dotnet/aspnetcore#50163 to consolidate functionality. The build won't pass until we consume that PR through an updated dependency, but everything builds and tests pass locally.

Fixes #4210 #4492 #4440 #4451

Major changes:

• Removed redundant types like middleware, request body handling, response body handling, media types, etc.
• Exception logging is delegated to the ExceptionHandling middleware, but we still log any request data we've accumulated so far.

Now that it's functional, parts of the original design should be revisited like the manual path filtering. We don't want to re-invent routing.

Microsoft Reviewers: Open in CodeFlow