Improve reference path and ID for individual work items
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### Challenge
- How useful is the full path to an object when shown in boards, roadmaps, breadcrumbs and other locations? How do users use this information?
- How might we make best use of the real estate we have within these items? For example, can we truncate the path at the beginning, middle or end?
- The current pattern, which shows the full path in all locations, results in details at the tail end of the path being truncated in some contexts — despite the tail being the most useful detail (e.g. project + IID)
### Instances for review
- Breadcrumbs
- Roadmaps
- Issue List
- Epic List
- Issue Board
- Epic Board
- Reference Popovers (Issue, Epic, MR)
- MR List
- Hierarchy Widget
* ...probably others I can't recall at the moment
| Epic tree | Roadmap | Board |
|-----------|---------|-------|
|  |  |  |
### Competitive analysis
To be completed in https://gitlab.com/gitlab-org/gitlab-design/-/issues/1530
### Proposal
`TBD`
### Resources & documentation
* :bookmark: **Documentation issue**
* :mag: **Research issue**: https://gitlab.com/groups/gitlab-org/-/epics/5214
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