[NT-634] Add backing ID to activities errored backings query

[justinswart]

📲 What

Adds the id field to the errored backings query for the activities tab.

🤔 Why

We had added id as an expected field for the GraphBacking model but forgot to update the query that requests this data causing deserialization to fail.

🛠 How

• Added id field to query.
• Updated test with actual response data.

✅ Acceptance criteria

• Having errored pledges, navigate to the activities tab, you should see errored pledges in the feed.