Work item widget bugfixes

What does this MR do and why?

Fixes some visual regressions related to work items which were introduced when migrating to the shared crud component:

• Linked items: Changes the icon from issue to link
• Spacing between action button and dropdown toggle
• Design management:
  • Fixes top spacing and enables collapsible feature
  • Fixes spacing between uploaded items
  • Fixing spacing in dropdown between avatar and text

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Check out an issue as work item, e.g. http://gdk.test:3000/flightjs/Flight/-/work_items/38

Related to #469616 (closed)

Closes #481900 (closed)