incorrect filter config provided to FilterGroups

The holdings and items segments pass the instance segment's filters to <FilterGroups>. This generates an NPE in <FilterGroups> (STCOM-623) because the values it receives in arguments.filters (i.e. the instance filters effectiveLocation, language, resource, location, staffSuppress, discoverySuppress) don't map to the value it receives in arguments.config, e.g. something like itemStatus.Checked out because itemStatus is not an instance filter.