Add Text-to-Image Support Using OpenAI Node

[shige]

Task description

Implement text-to-image functionality in the OpenAI node to allow image generation. This involves integrating the OpenAI Images API.

Background

The OpenAI API supports image generation from text prompts via the Images API. Adding this functionality to the node will allow developers to easily integrate image generation capabilities into their applications. This feature is documented at https://platform.openai.com/docs/api-reference/images.
The Vercel AI SDK already supports this with OpenAI and their documentation can be found here: https://sdk.vercel.ai/providers/ai-sdk-providers/openai#image-models.

const model = openai.image('dall-e-3');

TODO (Optional)

• Implement a function to call the OpenAI Images API with a text prompt.
• Allow configuration of image generation parameters.
• Handle API responses, including errors and image URLs.
• Add appropriate documentation and examples for using the new functionality.
• Add unit tests to ensure the image generation functionality works as expected.

Additional notes (Optional)

Consider using a similar approach to the Vercel AI SDK's implementation for image generation with OpenAI. Ensure that the implementation handles rate limiting and other potential API limitations gracefully.