fine-tune EXV interfacing for Argo
- automatically subset found r03 parameters to those accepted by the argopy library
- automatically choose the "ds" argument from the selected EXV
- add sparql wrapper in the requirement file (and move the import back up)
- add a few comments to mention status with EXV/R03 associations (3 parameters - pH, BBP, irradiance - are missing the necessary i-adopt mappings; Alex and Gwen were sollicited)