mgr/dashboard: fix remaining FA icon references and test failures

- Fix icon size mismatches and HTML lint errors
- Fix remaining FA icon references in tests
- Replace FA icons with Carbon in upgrade component:
  use cds-inline-loading for spinners, cd-icon for status icons
- Update test selectors for Carbon icon queries

Fixes: https://tracker.ceph.com/issues/76631
Signed-off-by: Afreen Misbah <afreen23@gmail.com>
Assisted-by: Claude