### 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)
NOTIFICATION_VISIBILITY_CHANGED = 30,
		NOTIFICATION_POST_POPUP = 31,
		NOTIFICATION_THEME_CHANGED = 32
	};
	void set_title(const String &p_title);
	String get_title() const;
	void set_initial_position(WindowInitialPosition p_initial_position);
	WindowInitialPosition get_initial_position() const;
	void set_current_screen(int p_screen);
	int get_current_screen() const;
	void set_position(const Point2i &p_position);
	Point2i get_position() const;
	void set_size(const Size2i &p_size);
	Size2i get_size() const;
	void reset_size();
	Point2i get_position_with_decorations() const;
	Size2i get_size_with_decorations() const;
	void set_max_size(const Size2i &p_max_size);
	Size2i get_max_size() const;
	void set_min_size(const Size2i &p_min_size);
	Size2i get_min_size() const;
	void set_mode(Mode p_mode);
	Mode get_mode() const;
	void set_flag(Flags p_flag, bool p_enabled);
	bool get_flag(Flags p_flag) const;
	bool is_maximize_allowed() const;
	void request_attention();
	void move_to_foreground();
	void set_visible(bool p_visible);
	bool is_visible() const;