Show state badge in work item sticky header for all states

What

Update the work item sticky header to display the state badge (WorkItemStateBadge) for all work item states instead of only when the item is closed. This matches the behavior of the main non-sticky header (work_item_created_updated.vue).

The v-if condition changed from workItemState === STATE_CLOSED to workItemState, and the now-unused STATE_CLOSED import was removed. The badge is still hidden when the work item is archived, as the archived badge takes precedence. Tests were updated to expect the badge to render for the Open state.

Before	After

Why

The sticky header only showed the state badge for closed work items, which was inconsistent with the main header. Showing the badge for all states gives users the same state information whether or not the header is stuck to the top of the viewport.