[Backend/Frontend] Extend Geocoding Interface to show POI

[ghost]

The current OpenLS response of a POI Adress search e.g. "Tankstelle Berlin" searches for POI, however the response is just the adress without further POI information (e.g. amenity=petrol_station). Therefore we could extend the XML interface to include POI information sth like: <xls:POI>petrol_station</xls:POI> and visualize this also within the client

Current response:
<xls:Address countryCode=""> <xls:StreetAddress> <xls:Building number="106"/> <xls:Street officialName="Dossenheimer Landstraße"/> </xls:StreetAddress> <xls:Place type="Country">Germany</xls:Place> <xls:Place type="CountrySubdivision">Baden-Württemberg</xls:Place> <xls:Place type="CountrySecondarySubdivision">Regierungsbezirk Karlsruhe</xls:Place> <xls:Place type="Municipality">Heidelberg</xls:Place> <xls:PostalCode>69121</xls:PostalCode> </xls:Address>