{
// required
id: Id; // import_preview id
import: boolean;
}
If import is True, use the rows from the given action worker and check that the import type
matches and whether it should still be created (row state new) or update (row state done). All
valid rows have a username. On row state new, the username must not exist yet. On row state done,
the record with the matching id should still have the same username. Don't build usernames or
default passwords. On error, don't import anything, but create data as in json_upload. Do the actual
import with bulk user.create and user.update actions.
The groups integrity check for non-template meetings from the json_upload will be repeated here.
If import is False or the import was successful, remove the action worker.
Permissions are analogue to user.create and user.update. Only allow importing data if there are
no errors in preview.