### 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)
default_texture->vp = const_cast<Viewport *>(this);
	viewport_textures.insert(default_texture.ptr());
	default_texture->proxy = RS::get_singleton()->texture_proxy_create(texture_rid);
	canvas_layers.insert(nullptr); // This eases picking code (interpreted as the canvas of the Viewport).
	set_positional_shadow_atlas_size(positional_shadow_atlas_size);
	for (int i = 0; i < 4; i++) {
		positional_shadow_atlas_quadrant_subdiv[i] = SHADOW_ATLAS_QUADRANT_SUBDIV_MAX;
	}
	set_positional_shadow_atlas_quadrant_subdiv(0, SHADOW_ATLAS_QUADRANT_SUBDIV_4);
	set_positional_shadow_atlas_quadrant_subdiv(1, SHADOW_ATLAS_QUADRANT_SUBDIV_4);
	set_positional_shadow_atlas_quadrant_subdiv(2, SHADOW_ATLAS_QUADRANT_SUBDIV_16);
	set_positional_shadow_atlas_quadrant_subdiv(3, SHADOW_ATLAS_QUADRANT_SUBDIV_64);
	set_mesh_lod_threshold(mesh_lod_threshold);
	String id = itos(get_instance_id());
	input_group = "_vp_input" + id;
	gui_input_group = "_vp_gui_input" + id;
	unhandled_input_group = "_vp_unhandled_input" + id;
	shortcut_input_group = "_vp_shortcut_input" + id;
	unhandled_key_input_group = "_vp_unhandled_key_input" + id;
	// Window tooltip.
	gui.tooltip_delay = GLOBAL_DEF(PropertyInfo(Variant::FLOAT, "gui/timers/tooltip_delay_sec", PROPERTY_HINT_RANGE, "0,5,0.01,or_greater"), 0.5);
#ifndef _3D_DISABLED
	set_scaling_3d_mode((Viewport::Scaling3DMode)(int)GLOBAL_GET("rendering/scaling_3d/mode"));
	set_scaling_3d_scale(GLOBAL_GET("rendering/scaling_3d/scale"));
	set_fsr_sharpness((float)GLOBAL_GET("rendering/scaling_3d/fsr_sharpness"));
	set_texture_mipmap_bias((float)GLOBAL_GET("rendering/textures/default_filters/texture_mipmap_bias"));
#endif 
	set_sdf_oversize(sdf_oversize); // Set to server.
}
Viewport::~Viewport() {