Bugfix for ensuring dc cross-collection facet/queries are filtered appropriately. Fixes DDK-151.
- Ensures that /dc cross-coll context does not issues queries filtering on parent collections (use admin set instead)
- Continues support for multi-collection portals (for now, not yet used); ensures up to 10 could be configured for a given portal (by local id)
- Maintains performance gains made in c2b2b5b8
- Minor rubocop fixes