Group work items list - epics list parity

Behind the work_item_epics_list feature flag, /-/epics shows work items instead of legacy epics. This issue tracks the work required to default the feature flag on.

Remaining issues:

• Fix `includeDescendants:false` returning nothin... (#480358 - closed) • Agnes Slota • 17.10
• Do not include descendants when filtering work ... (#520026 - closed) • Coung Ngo • 17.10
• Work items list - sort by start and due date (#463145 - closed) • Unassigned • Backlog • Needs attention
• Work Items list view - show discussion count (#478633 - closed) • Vedant Jain • 17.10

Prior to 2024-12-18

frontend:

• Add Start date and Due date sort options
• Use field userDiscussionsCount in UI
• Add search argument to workItemStateCounts
• Add page/browser history - #477345 (closed)
• Add bulk edit (!158762 (merged))
• Use field upvotes, downvotes (!161366 (merged))
• Show assignees in UI card
• Add empty states (!153129 (merged))
• Add filtered search (!150849 (merged), !159114 (merged), !159935 (merged))
• Add pagination (!151689 (merged))
• Add tab counts (!150499 (merged))
• Add include_descendants=true to GraphQL query (!155305 (merged))
• Start/Due dates for Epics doesn't seem to be working correctly (!155305 (merged))
• Add page size control (!156927 (merged))

backend:

• Fix includeDescendants:false returning nothing for subgroups (#480358 (closed))
• Change sidebar menu counter to use work items count - #474948 (closed)
• Add Start date and Due date sort options (#463145 (closed))
• Add missing field userDiscussionsCount so frontend can show number of discussions in UI - #478633 (closed)
• Add search argument to workItemStateCounts - #474948 (closed)
• Update issuesBulkUpdate mutation to also update group-level work items (#434296 (closed))
• Add missing search filters (#464757 (closed))
• Update workItemStateCounts to allow search filters, so frontend can get accurate counts when user searches/filters on the UI