Z-Image img2img and inpainting pipeline

[CalamitousFelicitousness]

Model/Pipeline/Scheduler description

I have written and opened a PR for implementation of img2img pipeline for Z-Image.

#12751

Open source status

• The model implementation is available.
• The model weights are available (Only relevant if addition is not a scheduler).

Provide useful links for the implementation

No response

[CalamitousFelicitousness]

Inpainting pipeline is also ready, to keep PR's more manageable I am going to wait with opening a PR for it until img2img is merged.