Gets the applicable ACL privilege for the apply and save tasks. The value returned is:
- @add if the record's ID is empty / record doesn't exist
- True if the ACL privilege of the edit task (@edit) is allowed
- @editown if the owner of the record (field user_id, userid or user) is the same as the logged in user
- False if the record is not owned by the logged in user and the user doesn't have the @edit privilege