Surface work item type in popovers, work item detail view

What does this MR do and why?

Moving from a world of issues to a world of work items with types, type is an increasingly important piece of context that should be elevated from a presentation standpoint. It shows the icon with type at 4 places where work items are visible.

• Show work item type in popovers
• Show work item type more prominently in the work item detail and legacy issue views.
• Show work item type in the issue list
• Add work item type icon to reference. If the work item is a work-item, use the id instead of iid.

P.S : The Task icon is not updated hence just shows an old one - this will be changed once the icon is updated

gitlab-svgs#321 (closed) - icon maps that should be visible

Screenshots or screen recordings

Master ( feature flag enabled )	MR ( feature flag enabled)

Master ( feature flag disabled )	MR ( feature flag disabled)

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

Example below:

1. In rails console enable the feature flag

   Feature.enable(:work_items)

2. Edit an issue's description to create some tasks, then save
3. Hover over a task, then click on the Create task + icon
4. Refresh the page so the task also appears in the linked issues widget (this UX bug will be fixed in a future MR)
5. Click on the task in the description and the task in the linked issues widget to confirm they open in a modal
6. To test incident scenario - click on new issue and select 'Incident' from the Type dropdown
7. Create a test as well while creating a test case from the 'Test case' submenu from CI/CD
8. Now when you open the issues list , you can see various types of work items

• Acceptance

• Work item type shows with each work item (or issue) in the issue list
• Work item type shows in popovers when hovered over a referenced work item (or issue). If type is a task, id in reference should be the id instead of the iid.
• Work item type shows more prominently in the work item (or legacy issue) view
• Work item type shows more prominently in the Linked Items widget (#366207 (comment 1016536322))
• [ ] Add work item type icon to reference. If the work item is a work-item, use the id instead of iid.

Related to #366207 (closed)