All editions can have limited access

Remove the can_limit_access? toggle because every edition type can now have limited access.

StatisticalDataSets are limited by default, as are Publications with a "statsy" PublicationType.  Also updated the UI for publications to toggle the limit access checkbox for new publications when the editor chooses a limiting publication type.  the migration makes access_limited a non-nullable field, and in passing updates all the NULL values to false.