### 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)
const int *constant = theme_constant_override.getptr(p_name);
	return constant != nullptr;
}
float Window::get_theme_default_base_scale() const {
	return theme_owner->get_theme_default_base_scale();
}
Ref<Font> Window::get_theme_default_font() const {
	return theme_owner->get_theme_default_font();
}
int Window::get_theme_default_font_size() const {
	return theme_owner->get_theme_default_font_size();
}
void Window::begin_bulk_theme_override() {
	bulk_theme_override = true;
}
void Window::end_bulk_theme_override() {
	ERR_FAIL_COND(!bulk_theme_override);
	bulk_theme_override = false;
	_notify_theme_override_changed();
}
Rect2i Window::get_parent_rect() const {
	ERR_FAIL_COND_V(!is_inside_tree(), Rect2i());
	if (is_embedded()) {
		
		Node *n = get_parent();
		ERR_FAIL_COND_V(!n, Rect2i());
		Viewport *p = n->get_viewport();
		ERR_FAIL_COND_V(!p, Rect2i());
		return p->get_visible_rect();
	} else {