Add `typeobj` to `dtype`
Add `typeobj` to `dtype`

Allows users to get the underlying `typeobj` (e.g. `numpy.float64`) from
the `dtype`.

scoder/cython,cython/cython,scoder/cython,cython/cython,cython/cython,da-woods/cython,da-woods/cython,scoder/cython,scoder/cython,da-woods/cython,cython/cython,da-woods/cython