feat(xo-6/dashboard): add S3 backup repository data

[OlivierFL]

Description

• Display S3 backup repository data on XO 6 dashboard.
• Add more detailed data to the backup repository section (added by feat(xo-server/rest-api/dashboard): add S3 backup repositories information #7978)
• Add polling to fetch the dashboard data, in case of backup repositories data calculation taking too long.

Screenshots

Checklist

• Commit
  • Title follows commit conventions
  • Reference the relevant issue (Fixes #007, See xoa-support#42, See https://...)
  • If bug fix, add Introduced by
• Changelog
  • If visible by XOA users, add changelog entry
  • Update "Packages to release" in CHANGELOG.unreleased.md
• PR
  • If UI changes, add screenshots
  • If not finished or not tested, open as Draft