Work Items - Breadcrumb to show parent work item

Problem

In the internal rollout of Tasks, users were confused about what a Task was and what it was related to.

For more background see: &6286 (comment 999844182), &8279 (comment 1003051069) and #363613 (closed)

Proposal

Show the parent issue in the breadcrumbs at the top of the page. This specifically refers to the new, full-page work item view (for example https://gitlab.com/gitlab-org/plan-stage/test-project/-/work_items/110192097).

• Replace Work items in the breadcrumb with Issues
• Display the Parent id breadcrumb after Issues
• Display the Child id in the last breadcrumb, after the "Parent ID`

Before	After