BUG: Index.get_slice_bounds does not accept datetime.date or tz naive datetime.datetimes
- [x] closes #35690
- [x] closes #34077
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

This method appeared under tested so added some additional tests for numeric and object `Index`
