rgw/notifications: Add tests for RGWPSListTopicsOp::execute()

rgw/notifications: Add tests for RGWPSListTopicsOp::execute()

Tests:
Add comprehensive test cases to verify the behavior of `RGWPSListTopicsOp::execute()` under various scenarios:

    Migration case: Validate correct handling when `support_all_zones` is enabled, with v1 in a new state after migration and v2 topics present.
    v2 notification case: Ensure proper retrieval when v2 notifications are supported.
    v1 notification case: Verify fallback behavior when v2 notifications are unavailable.

Enhancements:
    Update `delete_all_topics` to handle v1 responses with the `result` key.

fixes: https://tracker.ceph.com/issues/68756
Signed-off-by: Oshrey Avraham <oshrey16@gmail.com>