Uses separate denoiser for edit (instruct-pix2pix) models
No impact to txt2img or regular img2img
"Image CFG Scale" will only apply to instruct-pix2pix models and metadata will only be added if using such model
Allows loading instruct-pix2pix models via same method as inpainting models in sd_models.py and sd_hijack_ip2p.py
Adds ddpm_edit.py necessary for instruct-pix2pix