TST: add new test - check reindex() and astype() order consistency for Series
check reindex() and astype() order consistency for Series

- [x] closes #17444
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

thanks @ganevgv 