Kolors additional pipelines, community contrib

[Teriks]

These are primarily ControlNet pipelines for Kolors.

Adapted from: https://github.com/Kwai-Kolors/Kolors

For direct use with diffusers existing ControlNetModel + an additional pipeline for inpainting.

Compatibility with diffusers ControlNetModel is accomplished via temporary patching of the ControlNetModel instance, (no global side effects such as modifying the class itself)

This supports MultiControlNetModel as well.

Pipelines here:

KolorsControlNetPipeline
KolorsControlNetImg2ImgPipeline
KolorsControlNetInpaintPipeline
KolorsInpaintPipeline

Complete doc with example strings, but could use a look over.

Wish to contribute these to community pipelines, these could be of reference (or adapted) to implement these pipelines in mainline diffusers if desired.

I wrote these for integration into a personal project (CLI/GUI) tool, and they have been tested somewhat thoroughly.

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Did you read the contributor guideline?
• Did you read our philosophy doc (important for complex PRs)?
• Was this discussed/approved via a GitHub issue or the forum? Please add a link to it if that's the case.
• Did you make sure to update the documentation with your changes? Here are the
  documentation guidelines, and
  here are tips on formatting docstrings.
• Did you write any new necessary tests?

Who can review?

@sayakpaul @yiyixuxu @asomoza

Anyone in the community is free to review the PR once the tests have passed. Feel free to tag
members/contributors who may be interested in your PR.