Fix work item alert position

Page-level alerts in work items appear in a sticky position near the top of the page, originally inherited from legacy issues. However the position is a bit awkward.

In the drawer view, the alert always overlaps content, even when not scrolled. In the full page view, the alert overlaps the sticky header when present.

State Drawer Full page
Not scrolled

image.png

image.png
Scrolled

image.png

w/ sticky header

image.png

image.png

Design proposal

  1. When not scrolled, ensure the alert is at the top of the detail body (Full page view is currently correct, drawer is not)
  2. When scrolled, ensure alert is directly below any sticky headers (neither is correct)
Edited by 🤖 GitLab Bot 🤖