resource_scope: Propagate source location tracking

[SpecificProtagonist]

Objective

Part of #16775

If a resource is mutated in resource_scope, store the tracked source location.

Showcase

This used to print the location of the insert_resource call; it now prints the location of the deref_mut call:

#[derive(Resource)]
struct A;
let mut world = World::new();
world.insert_resource(A);
world.resource_scope::<A, _>(|_, mut a| {
    a.deref_mut();
});
dbg!(world.resource_ref::<A>().changed_by());