## What this PR does
Add representation for backup Plans, BackupJobs and Backups in the dashboard and a readme
describing, how to add further resources to the dashboard.
### Release note
```release-note
[backups,dashboard] Add backup Plans, BackupJobs, and Backups to the dashboard.
```
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Added a Backups section in the dashboard navigation with Plans,
BackupJobs, and Backups.
* Added detailed views for Plan, BackupJob, and Backup showing metadata,
references, status, timings, and artifacts.
* Enhanced list views with custom columns (application refs,
phase/status, created/taken timestamps).
* **Documentation**
* Added a Dashboard integration guide documenting how to add resources,
list/detail wiring, and verification steps.
<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
(cherry picked from commit 67c526582a)
Signed-off-by: Timofei Larkin <lllamnyp@gmail.com>
6cd06ced9a