Dataset types should have a display name and a description

[pdurbin]

Currently dataset types have an id and a name.

As discussed during standup today, there should also be a display name.

Update: later, we also realized dataset types should have a description to support the UI (below) in this pull request:

• Dataset Type selection step in Create Dataset page dataverse-frontend#876

We came to this conclusion in the context of IQSS/dataverse-frontend#845 where I'm adding a entry like "newReview": "New Review", in a file for English strings but this won't work because superusers can add whatever types they want.

From https://guides.dataverse.org/en/6.8/schemaspy/tables/datasettype.html