BUG: dropna() on single column timezone-aware values (#13407)
- [x] closes #13407
- [x] tests added / passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

As mentioned by the title of #13407, DataFrame.values not a 2D-array when constructed from timezone-aware datetimes. Hence, ``notna(frame.values)`` raises ``ValueErorr: 'axis' entry is out of bounds`` because user tries to apply ``dropna`` on a 1D-array.

I mainly include the example mentioned by the original author of #13407. Let me know if further test examples are required for this issue. Thanks.

Edit: I add additional test example to demonstrate the dropping of np.nan and None from the Series having timezone-ware datetimes.