Comfyui (Dify)

by @langgenius

[ComfyUI](https://www.comfy.org/) is the most powerful and modular diffusion model GUI, API and backend with a graph/nodes interface. Now you can use it in Dify, input the prompt or images, and get the generated image. It is highly recommended to install [comfy-asset-downloader](https://github.com/ServiceStack/comfy-asset-downloader.git) on your ComfyUI server as this plugin needs it to download m