Filter duplicate datasets

[ryscher]

Remove dataset duplicates --

• Figshare items with same title, authors
• Zenodo items with same title, authors

Ensure the importer detects duplicates, and doesn't create a dataset with the same name and authors.

[ryscher]

TODO: Working in duplicate datataset remover --- identifies dups by title.

• Should check authors as well,
  • it's not completely working, because datasets coming out of the search system don't have the ID embedded in their metadata -- probably need to insert it so the method works properly
• then delete.
• then expand to all the previously imported datasets

[ryscher]

TODO: modify the importer so it doesn't create duplicates --> Seems mostly done, but running a new import; after it's done, run the duplicate remover and see whether there are any that were created.

[ryscher]

The importer mostly doesn't create duplicates, and it's simple enough to run the duplicate remover to double-check afterwards.