Support raw error responses

[DanielHabenicht]

Confirm this is a feature request for the Node library and not the underlying OpenAI API.

• This is a feature request for the Node library

Describe the feature or improvement you're requesting

With the current version its is possible to have undocumented request parameters and response parameters. But if one also returns undocumente errors which are not matching the openai layout the response is basically not accessible.

It would be nice if the error could contain a .raw property which allows to access the original body and headers.

Additional context

e.g. this would be possible:

try {
  new OpenAI({...}).chat.completions.create({
        model,
        messages,
        stream: true
      });
} catch (error) {
  // Access undocumented properties, e.g. RFC specified error properties
  console.log(error.detail)
}
```

[RobertCraigie]

This already exists!

openai-node/src/core/error.ts

Lines 12 to 17 in 862e363

	/** HTTP status for the response that caused the error */
	readonly status: TStatus;
	/** HTTP headers for the response that caused the error */
	readonly headers: THeaders;
	/** JSON body of the response that caused the error */
	readonly error: TError;

[DanielHabenicht]

Then it might be an error report instead as error is always undefined for us?
We provide a body:

but get this error:

[DanielHabenicht]

I found the place where it is undefined for our response, as error is not the error Response but only the error field inside the response:

openai-node/src/core/error.ts

Line 69 in 27f77c8

const error = (errorResponse as Record<string, any>)?.['error'];

Should I edit it to be the error Response (as documented) or should we add another property to be backwards compatible?