Response data format in context are not the same after upgraded to v4
### Issue Description

I just migrated apollo-server-express from v3 to v4 successfully by following the official [documentation ](https://www.apollographql.com/docs/apollo-server/migration/#migrate-from-apollo-server-express)

But now response data format in plugins context are not the same after upgraded to v4.

Let me explain, I have a plugin that will take information from the cookies.  In a few lines :
```
requestDidStart() {
  return {
    willSendResponse({ operation, response }) {
      .....
      const data = response.data
```

Before with v3, I could get this information directly with `response.data`, but now, since v4 I have to use `response.body.singleResult.data`

Is it right? I have not found any documentation on this subject. Can you please comment on this change? Thank you in advance for your feedback.

### Link to Reproduction

-

### Reproduction Steps

_No response_