### Godot version

v4.0.3.stable.official [5222a99f5]

### System information

Windows 10

### Issue description

If a `CharacterBody3D`'s parent node is in a position other than the origin, the difference will be included in its `get_position_delta()` value, and therefore also `get_real_velocity()`. This is because [the implementation](https://github.com/godotengine/godot/blob/3710f069293f2fde8afe33fea898c4b36fa5e943/scene/3d/physics_body_3d.cpp#L1782-L1784) subtracts the current **local** transform from the old **global** transform. I don't know if behaviour in this case is defined at all, but I would expect it to be consistent with everything else in the `CharacterBody3D` context, such that if `velocity` is zero, `get_position_delta()` is also zero. The same applies to `CharacterBody2D`.

### Steps to reproduce

1. Create a `Node3D` with a `CharacterBody3D` in it
2. Move the `Node3D`
3. Call `move_and_slide()` in the `CharacterBody3D` and observe `get_position_delta()`

### Minimal reproduction project

[godot cb3d.zip](https://github.com/godotengine/godot/files/11861307/godot.cb3d.zip)

real_velocity = get_position_delta() / delta;
	if (platform_on_leave != PLATFORM_ON_LEAVE_DO_NOTHING) {
		
		if (!collision_state.floor && !collision_state.wall) {
			if (platform_on_leave == PLATFORM_ON_LEAVE_ADD_UPWARD_VELOCITY && current_platform_velocity.dot(up_direction) < 0) {
				current_platform_velocity = current_platform_velocity.slide(up_direction);
			}
			velocity += current_platform_velocity;
		}
	}
	return motion_results.size() > 0;
}
void CharacterBody3D::_move_and_slide_grounded(double p_delta, bool p_was_on_floor) {
	Vector3 motion = velocity * p_delta;
	Vector3 motion_slide_up = motion.slide(up_direction);
	Vector3 prev_floor_normal = floor_normal;
	platform_rid = RID();
	platform_object_id = ObjectID();
	platform_velocity = Vector3();
	platform_angular_velocity = Vector3();
	platform_ceiling_velocity = Vector3();
	floor_normal = Vector3();
	wall_normal = Vector3();
	ceiling_normal = Vector3();
	
	
	bool sliding_enabled = !floor_stop_on_slope;
	
	bool can_apply_constant_speed = sliding_enabled;