Added support to query full geometry from Nominatm.

Added support for a  'geometry' attribute to geolocator.geocode which accepts either 'geojson', 'kml', 'svg' or 'WKT' as a value and returns the full geometry of a result in result.raw in the given format.wq
Can we do these as `elif`, and end with an `else: raise GeocoderQueryError("Invalid...")` or such?