[release/6.0] Log time-taken more precisely (#36066)

* Log time-taken more precisely

* Log to other field

* Feedback

* Update src/Middleware/HttpLogging/src/W3CLoggingMiddleware.cs

Co-authored-by: Kahbazi <akahbazi@gmail.com>

* Fix test

* Feedback

Co-authored-by: Will Godbe <wigodbe@microsoft.com>
Co-authored-by: Kahbazi <akahbazi@gmail.com>