TST closes #28980 Certain comparison operations misbehaving for period dtype
I've added test to compare `pd.Series([...], dtype="period[A-DEC]")`  to dtype `str`, `bool`, `int`, `float` and `None`.

- [ x ] closes #28980
- [ 5 ] tests added / passed
- [ x ] passes `black pandas`
- [ x ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
