Use numpy.typing throughout the code

[hello-cpaxton]

          FYI, np has a `typing` module that allows for richer and more compact type annotations. See [here](https://numpy.org/devdocs/reference/typing.html#numpy.typing.NDArray) for an example.

    def grasp_open_loop(self, object_xyz: npt.NDArray[np.float32]):

Originally posted by @hello-amal in #16 (comment)