Expose per-request telemetry for number of bytes sent from client to server.

IIS exposes telemetry about number of bytes sent from client to server on a per-request basis. Please see "Client bytes sent" in https://docs.microsoft.com/en-us/windows/win32/http/iis-logging. This is a request to enable similar telemetry for HTTP.sys server and Kestrel. This is useful for ingress bandwidth calculations/investigations for large-scale services.