Add http.route.response span

[stayallive]

This Laravel PR gifted us insight in the preparing of a response: laravel/framework#47229.

We can use that to add a http.route.response span which will identify possible actions taken to prepare the response, especially when using Illuminate\Contracts\Support\Responsable classes.

Before:

After:

In the example it's just a fake sleep span, but any number of things can happen to prepare the response like running queries and/or making HTTP calls which would be very nice to have grouped under http.route.response instead of directly under middleware.handle.

This will also cause view rendering to be grouped under this new span since views also are only rendered after being returned from the route handler (controller/closure etc.):

Note: You need Laravel 10.13.0 for this to work!

Happy to take suggestions on better naming!