Sync prompt API

[filipemeneses]

Assuming that implementing websocket adds complexity to other systems that use ComfyUI API, having a sync HTTP endpoint that awaits the workflow to finish can be a solution.

To implement, this instructions should work:

• Add POST /prompt_sync endpoint. This endpoint waits the prompt_id to be executed, adds a callback function on a map.
• Add POST /prompt_finish endpoint. This endpoint triggers a callback function from a map according to prompt_id
• Add node Finish workflow with image. This node trigers /prompt_finish with the image and prompt_id

[abaybektursun]

+1

[RayKitajima]

I am temporarily using bridge service. https://github.com/RayKitajima/ComfyBridge