BUG: equals/assert_numpy_array_equals with non-singleton NAs
- [ ] closes #xxxx
- [x] tests added / passed
- [x] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them
- [ ] whatsnew entry

> Eg currently we have see None or np.nan as equivalent:

good catch, this changes that.  will update to keep current behavior (though id be OK with deprecating it separately) whatsnew added + green