### Godot version

v4.0.beta17.official [c40020513]

### System information

macOS 13.0.1

### Issue description

When a `Control` node is over a `SubViewportContainer` (with a `SubViewport` as a child), both in Full Rect anchors, asking for the get_viewport().get_mouse_position() from a scene inside the `SubViewport` returns (0, 0) as the position of the mouse.

This wasn't happening in at least Beta 15. I was getting the mouse position without any problems before Beta 17. I didn't try Beta 16.

### Steps to reproduce

1. Create a `Control` node
2. Add two children: A `SubViewportContainer` and a `Control` node
3. Put both in Full Rect anchors so the `Control` node (child) is covering the `SubViewportContainer`
4. Ask for the get_viewport().get_mouse_position() from inside a scene of the `SubViewport`

As you can see in this screenshot: asking for the mouse position from inside the `Node2D` script always returns (0, 0).

<img width="1533" alt="SubViewportContainerIssue" src="https://user-images.githubusercontent.com/91340577/217051768-d9c2e8ad-40ca-4c6d-bb98-f6a7c9c6081f.png">

Only If the `Control` (child) mouse filtering is set to _Ignore_ you can get the mouse position. But with that you are losing the mouse inputs from that `Control` node.

You can find the setup of these nodes in the MRP.


### Minimal reproduction project

Run the main scene (control.tscn) and move the mouse around the screen. Look for the print in the Output tab.

[SubViewportMousePositionIssue.zip](https://github.com/godotengine/godot/files/10667894/SubViewportMousePositionIssue.zip)
update_mode = p_mode;
	RS::get_singleton()->viewport_set_update_mode(get_viewport_rid(), RS::ViewportUpdateMode(p_mode));
}
SubViewport::UpdateMode SubViewport::get_update_mode() const {
	return update_mode;
}
void SubViewport::set_clear_mode(ClearMode p_mode) {
	clear_mode = p_mode;
	RS::get_singleton()->viewport_set_clear_mode(get_viewport_rid(), RS::ViewportClearMode(p_mode));
}
SubViewport::ClearMode SubViewport::get_clear_mode() const {
	return clear_mode;
}
DisplayServer::WindowID SubViewport::get_window_id() const {
	return DisplayServer::INVALID_WINDOW_ID;
}
Transform2D SubViewport::get_screen_transform() const {
	Transform2D container_transform;
	SubViewportContainer *c = Object::cast_to<SubViewportContainer>(get_parent());
	if (c) {
		if (c->is_stretch_enabled()) {
			container_transform.scale(Vector2(c->get_stretch_shrink(), c->get_stretch_shrink()));
		}
		container_transform = c->get_viewport()->get_screen_transform() * c->get_global_transform_with_canvas() * container_transform;
	} else {
		WARN_PRINT_ONCE("SubViewport is not a child of a SubViewportContainer. get_screen_transform doesn't return the actual screen position.");
	}
	return container_transform * get_final_transform();
}
Transform2D SubViewport::get_popup_base_transform() const {