sendpay_failure notifications missing important fields

cln v24.05:
apparently some fields are missing from `sendpay_failure` notifications:
```
sendpay_failure notification: {\"sendpay_failure\":{\"code\":204,\"message\":\"failed: WIRE_UNKNOWN_NEXT_PEER (reply from remote)\",\"data\":{\"created_index\":8398,\"id\":8398,\"payment_hash\":\"a6ac55c126b415f9236526fbb6e8c847db5dc1da94db148f85db512ca3dc0c82\",\"groupid\":2,\"partid\":1,\"destination\":\"03f060953bef5b777dc77e44afa3859d022fc1a77c55138deb232ad7255e869c00\",\"amount_msat\":5311800403,\"amount_sent_msat\":5311859832,\"created_at\":1719325305,\"status\":\"pending\",\"erring_index\":1,\"failcode\":16394,\"failcodename\":\"WIRE_UNKNOWN_NEXT_PEER\",\"raw_message\":\"400a\"}}}
```

missing:

- `erring_node`
- `erring_channel`
- `erring_direction`

Also notice how `status` is `pending` instead of `failed` as promised by the docs:

https://docs.corelightning.org/docs/event-notifications#sendpay_failure

This makes the notification far less useful and also causes a panic in `cln-plugin` because it expects these fields.