Addfips

- Explicitly open files as UTF-8 to avoid errors in polluted environments.

* Update packaging methods
* Remove `importlib_resources` dependency for newest versions of Python (3.9+)
* Expand tests

- improve/generalize abbreviation handling
- fix bug when --no-header is set and a field index is zero

- Add err-unmatched CLI option for sending unmatched rows to stderr
- Add 2010 county file
- Adjust fuzzy matching to simplify loading data

- Recognize "Saint" as well as "St."
- Recognize more variations on DC
- Check if passed state is a FIPS