TYP: add a few type annotations to `numpy.array_api.Array`
TYP: add a few type annotations to `numpy.array_api.Array`

This fixes the majority of the complaints for `$ mypy numpy/array_api`.
The comment indicating that one fix is blocked by lack of support in
Mypy for `NotImplemented` is responsible for another several dozen
errors.

[skip ci]

mattip/numpy,charris/numpy,pdebuyl/numpy,numpy/numpy,mhvk/numpy,endolith/numpy,seberg/numpy,seberg/numpy,jakirkham/numpy,anntzer/numpy,mattip/numpy,charris/numpy,endolith/numpy,numpy/numpy,mhvk/numpy,seberg/numpy,mhvk/numpy,mattip/numpy,pdebuyl/numpy,jakirkham/numpy,anntzer/numpy,jakirkham/numpy,anntzer/numpy,pdebuyl/numpy,rgommers/numpy,charris/numpy,anntzer/numpy,numpy/numpy,pdebuyl/numpy,jakirkham/numpy,endolith/numpy,seberg/numpy,mhvk/numpy,rgommers/numpy,numpy/numpy,mattip/numpy,endolith/numpy,rgommers/numpy,jakirkham/numpy,rgommers/numpy,mhvk/numpy,charris/numpy