Add 700n 96 and 97

* add test
* differentiate between "Kreis" and "Regierungsbezirk" improving results

See hbz/nwbib#53
Merge pull request #592 from lobid/issues-53-hbz-nwbib-700n96-97-KreisRegierungsbezirk

Add 700n 96 and 97