HM/JPM: drilldownFields in FieldRegistry, CQL query on FacetFields enabled; TODO: fix unit test and integration test
HM/JPM: no longer creating separate search field in case it is supposed to be available as FacetField as well.
HM/JPM: only splitting drilldown query values on '>' for hierarchical drilldown fields + allowing remote invocation of 'drilldownFieldnames'