When a role `xx` has `grant select (name) on items to xx;`, a generic table-level error is given:
select * from items; ERROR: permission denied for table items
With this patch, we now give:
select * from items; ERROR: permission denied for column "id" of relation "items"
This only when the user has column-level privileges, if it doesn't have any the same regular table-level error is given. This makes the most sense and also keeps current tests mostly the same.