improve shape-typing and returned dtypes in `numpy._core.numeric`

- [ ] `ones` and `full`
- [ ] `zeros_like`, `ones_like`, and `full_like`
- [ ] `count_nonzero` (only dtypes)
- [ ] `argwhere` (only shape-typing)
- [ ] `correlate` and `convolve` (only dtypes)
- [ ] `cross`
- [ ] `outer` (only dtypes)
- [ ] `tensordot`
- [ ] `roll`
- [ ] `rollaxis`
- [ ] `moveaxis`
- [ ] `indices`
- [ ] `identity`
- [ ] `isclose` (only shape-typing)
- [ ] `astype` (only dtypes)