geo_file_registry does have updated_at column

On the Geo Admin panel for uploads we sort the registries by date, and we also display the date. But that date is the created_at timestamp. It would make much more sense if that would be the updated_at date. But that column does not exist yet.

Proposal

• Add migration to add the updated_at column
• Display that date instead of created_at
• Sort the fresh scope on updated_at too