BUG: Add unordered option to pandas.cut (#33141)
Added tests and error message when there are no labels and `ordered=False`.

Issue: Pandas cut raises error if labels are non-unique (Closes #33141)

- [x] closes #33141 
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry
