| Convert "data" to a PostGIS url
Candidates for conversion are:
- URL - from browser DnD
- PostGISServiceImpl - from catalog DnD
- IService - from search DnD
No external processing should be required here, it is enough to guess and let
the ServiceFactory try a real connect.
Parameters: data - IService, URL, or something else URL considered a possibility for a PostGIS connection, or null |