### 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)

if (slide_motion.dot(velocity) > 0.0) {
						motion = slide_motion;
					} else {
						motion = Vector3();
					}
					if (slide_on_ceiling && result_state.ceiling) {
						
						if (vel_dir_facing_up) {
							velocity = velocity.slide(collision.normal);
						} else {
							
							velocity = up_direction * up_direction.dot(velocity);
						}
					}
				}
				
				else {
					motion = result.remainder;
					if (result_state.ceiling && !slide_on_ceiling && vel_dir_facing_up) {
						velocity = velocity.slide(up_direction);
						motion = motion.slide(up_direction);
					}
				}
			}
			total_travel += result.travel;
			
			if (p_was_on_floor && floor_constant_speed && can_apply_constant_speed && collision_state.floor && !motion.is_zero_approx()) {
				Vector3 travel_slide_up = total_travel.slide(up_direction);
				motion = motion.normalized() * MAX(0, (motion_slide_up.length() - travel_slide_up.length()));
			}