feat: add image generation with ncnn-stablediffusion

[mudler]

Example with curl:

curl http://localhost:8080/v1/images/generations -H "Content-Type: application/json" -d '{
            "prompt": "floating hair, portrait, ((loli)), ((one girl)), cute face, hidden hands, asymmetrical bangs, beautiful detailed eyes, eye shadow, hair ornament, ribbons, bowties, buttons, pleated skirt, (((masterpiece))), ((best quality)), colorful|((part of the head)), ((((mutated hands and fingers)))), deformed, blurry, bad anatomy, disfigured, poorly drawn face, mutation, mutated, extra limb, ugly, poorly drawn hands, missing limb, blurry, floating limbs, disconnected limbs, malformed hands, blur, out of focus, long neck, long body, Octane renderer, lowres, bad anatomy, bad hands, text",
            "size": "256x256"
          }'

mode=0	mode=1 (winograd/sgemm)

This PR adds golang bindings for https://github.com/EdVince/Stable-Diffusion-NCNN in order to generate images with stable diffusion.

Currently supports up to 512x512 image size.

To enable: make GO_TAGS=stablediffusion build
Requires: opencv, libgomp

[sumersm7]

how to use diffrent models with this. or where to get models compatible with ncnn.