rename position_x, position_y, position_z to offsets #499

We should probably rename all the position_<axis> properties to offsets since that's where the WorldObject is placed and does not indicate the buffer data, ex. positions geometry.

realized when doing #498 that this can get confusing

Maybe have:

class Graphic
@offset.setter
def offset(self, offset: tuple[float, float, float]):
  x, y, z = offset
  self.world_object.world.x = x
  ...