### 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)
switch (p_what) {
		case NOTIFICATION_ENTER_TREE: {
			if (get_parent()) {
				parent = get_parent()->get_viewport();
				RenderingServer::get_singleton()->viewport_set_parent_viewport(viewport, parent->get_viewport_rid());
			} else {
				parent = nullptr;
			}
			current_canvas = find_world_2d()->get_canvas();
			RenderingServer::get_singleton()->viewport_attach_canvas(viewport, current_canvas);
			RenderingServer::get_singleton()->viewport_set_canvas_transform(viewport, current_canvas, canvas_transform);
			RenderingServer::get_singleton()->viewport_set_canvas_cull_mask(viewport, canvas_cull_mask);
			_update_audio_listener_2d();
#ifndef _3D_DISABLED
			RenderingServer::get_singleton()->viewport_set_scenario(viewport, find_world_3d()->get_scenario());
			_update_audio_listener_3d();
#endif 
			add_to_group("_viewports");
			if (get_tree()->is_debugging_collisions_hint()) {
				PhysicsServer2D::get_singleton()->space_set_debug_contacts(find_world_2d()->get_space(), get_tree()->get_collision_debug_contact_count());
				contact_2d_debug = RenderingServer::get_singleton()->canvas_item_create();
				RenderingServer::get_singleton()->canvas_item_set_parent(contact_2d_debug, find_world_2d()->get_canvas());
#ifndef _3D_DISABLED
				PhysicsServer3D::get_singleton()->space_set_debug_contacts(find_world_3d()->get_space(), get_tree()->get_collision_debug_contact_count());
				contact_3d_debug_multimesh = RenderingServer::get_singleton()->multimesh_create();
				RenderingServer::get_singleton()->multimesh_allocate_data(contact_3d_debug_multimesh, get_tree()->get_collision_debug_contact_count(), RS::MULTIMESH_TRANSFORM_3D, false);
				RenderingServer::get_singleton()->multimesh_set_visible_instances(contact_3d_debug_multimesh, 0);