Updating demo content:
- Added extra user "alfrednobel".
- Added extra group "Nobel Prize".
- Added discussions in the "Nobel Prize" group.
- Added missing "Topics" to the Discussions.
- Added missing "Type of Discussion" to the discussions.
Granted all users the permission to sort the search_api search results.
Added extra test steps to the "Discussions overview" feature.
Fixed permissions & demo data.