- Restructure valueset pages from single master page to separate views:
- Library Valuesets (read-only lookup browser)
- Result Valuesets (CRUD for valueset table)
- Valueset Definitions (CRUD for valuesetdef table)
- Add new ResultValueSetController for result-specific valueset operations
- Move views from master/valuesets to result/valueset and result/valuesetdef
- Convert valueset sidebar to collapsible nested menu
- Add search filtering to ValueSetController index
- Remove deprecated welcome_message.php and old nested CRUD view
- Update routes to organize under /result namespace
Summary of changes: This commit reorganizes the valueset management UI by splitting the monolithic master/valuesets page into three distinct sections, adds a new controller for result-related valueset operations, and restructures the sidebar navigation for better usability.