Add top-level creation URL for global scope (#37342)

Global scopes have two creation URLs: one for itself and one for the
"top-level" scope. It's not immediately obvious what is considered
top-level here (it is not strictly defined in the specification).

In any case, reports need the creation URL of the scope itself, not the
top-level version. Therefore, propagate this information from all
scopes, where the worker and worklets remain to pass in `None` for their
top-level scope.

Part of #37328

---------

Signed-off-by: Tim van der Lippe <tvanderlippe@gmail.com>

components/script/dom/workerglobalscope.rs

@@ -171,6 +171,7 @@ impl WorkerGlobalScope {
                 init.resource_threads,
                 MutableOrigin::new(init.origin),
                 init.creation_url,
+                None,
                 runtime.microtask_queue.clone(),
                 #[cfg(feature = "webgpu")]
                 gpu_id_hub,