[Feature Request]: Multi-stage processing (like highres fix)

[A2Sumie]

Is there an existing issue for this?

• [X] I have searched the existing issues and checked the recent builds/commits

What would your feature do ?

Current highres fix involves 2 stages to help eliminating horrible outputs on high resolutions. Yet this feature could also help keeping natural human bodies or certain poses while maintaining desired aspect ratio, or cleaning up artifacts and bringing crisper results. A multi-stage workflow implemented in the webui could bring automation to these needs, instead of manually throwing results into img2img many times.

Proposed workflow

1. Go to txt2txt or img2txt
2. Option checkbox "multi-stage sampling" under sampling methods.
3. After checking, a slider appears that allows choosing of desired number of passes.
4. Slider groups appear. Number corresponding to selected passes.
5. Sliders width, height, denoising strength in a single slider group.
6. Highres fix checkbox goes away.

Additional information

No response