`HttpContext` copies in `MultiplexingMiddleware` even if 1 downstream route defined

[ggnaegi]

Expected Behavior / New Feature

• The Middleware code is readable and can be easily modified by contributors.
• There is no copy of the http context when only one downstream route is defined.
• When there is a single route, it is processed immediately, without going through the multiplexing logic of the middleware.

  Actual Behavior / Motivation for New Feature

  In most cases, a single downstream route is defined. In the middleware, however, a copy of the context is created, whereas in the case of a single route this is not necessary, as only one task is started and not several in parallel.

The middleware code is also very complicated to read, even though it is an important part of the application code.

[raman-m]

Yeah, Multiplexing feature is a hard nut... Thank you for design review! 💪 So, I agree this feature can be refactored and redesigned a bit to improve performance...

In my opinion, this is complex feature and it affects performance, it is better to include this design rework into next upcoming release, but not Nov'23, and seems not Dec'23 releases... Probably we can work on this issue in Jan'24... 🆗 ❔