| Convert "data" to a wfs capabilities url
Candidates for conversion are:
- URL - from browser DnD
- URL#layer - from browser DnD
- WFSService - 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 WFS Capabilities, or null |