Remove TestData from series-tests test_repr.py
Part of #22550

* Replaced TestData usage in `pandas/tests/series/test_repr.py` with fixtures

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

I added a new `empty_series` fixture as it is mentioned in the issue description. I've seen more places where this can be used, so I hope this is fine with you Done ✅ Please have another look @jreback thanks