This testcase ensures:
1. Storage permission is propagated to same-origin iframes in the same tab
2. Storage permission is propagated to same-origin iframes that have the same
top-level in the same agent-cluster
3. Storage permission is NOT propagated to same-origin iframes that don't have
the same top-level in the same agent-cluster
4. Storage permission is NOT propagated to same-origin iframes that have
the same top-level but not in the same agent-cluster
We also run above tests when storage permission is granted on a first-party window
and storage permission is granted on a 3rd-party window.
Depends on D78135
Differential Revision: https://phabricator.services.mozilla.com/D78136