Fix gfz institute name

After seeing a difference in the GFZ legal notes page & the name on the ROR page, we realized that we need to make a minor fix on the GFZ institute name.

It should be Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences (https://www.gfz-potsdam.de/en/legal-notice) and not Helmholtz Centre Potsdam - German Research Centre for Geosciences GFZ (so without the minus).

Changes in the repo:

• change in the organizations list
• migration for the database.