Fix get_species_status

[ka7eh]

The script assumes all species in data/index_species_verified.json are from WoRMS dataset, though that's not the case and entries can be from various sources. Details of all available data sources are in data/data_sources.json. An example is gn_2175388, which comes from Arctos.

We should update the script so it uses the correct URL, if one exists, for each species.