Update transformation of "containedIn" and "rs""

- Add lookup of geonames ids using "Gemeindeschlüssel"
(this number can be found in Sigel field  032P.n but has to be
decoded from DBS field "gemeindekennzahl")
- Fix regular expression to extract "Gemeindekennzahl" from DBS
during transformation of "rs" ("Regionalschlüssel")
Fix transformation of "sameAs", "wikipedia", "isPrimaryTopicOf"

Use field "isil" instead of "008H.e" since "008H.e" is transformed
into "isil" in an earlier step
Add transformation of "ags" for both Sigel and DBS data

(ags = Amtlicher Gemeindeschlüssel)