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/workletglobalscope.rs

@@ -104,6 +104,7 @@ impl WorkletGlobalScope {
                 script_to_constellation_chan,
                 init.resource_threads.clone(),
                 MutableOrigin::new(ImmutableOrigin::new_opaque()),
+                base_url.clone(),
                 None,
                 Default::default(),
                 #[cfg(feature = "webgpu")]