Add fallback value to requests

[bryanjtc]

Describe the bug
If a request fails react query throws this error because data cannot be undefined
Query data cannot be undefined. Please make sure to return a value other than undefined from your query function

To Reproduce
Steps to reproduce the behavior:

1. Use any query generated by this tool and make it throw an error

OpenAPI spec file
If possible, please upload the OpenAPI spec file.

Expected behavior
Allow adding a fallback value like null, or an empty array or empty string

Screenshots

• OS: [e.g. macOS]
• Version [e.g. v1.0.0]

Additional context
Add any other context about the problem here.

[nickdaugherty]

I found a workaround - set throwOnError: true in the client options:

import { client } from './api/requests/services.gen.js';

client.setConfig({
    throwOnError: true,
});

The problem is errors aren't being thrown, leading to TanStack Query thinking the request succeeded. Related, the onSuccess() callback is also being incorrectly called as a result of this.