- Adds the /collections/ua-record-groups browse page
- Revises how the group/subgroup values get indexed (use the full titles instead of the numbers)
- Implements the blacklight-hierarchy gem but patch its incompatibility with view_component v3
- Implements blacklight-hierarchy JS without jQuery (use its ES6 Stimulus controller but patch its bugs)
- Displays the linked group/subgroup values on the collection page (summary section)