Several fixes to Flux ControlNet pipelines

[vladmandic]

Adds several fixes to Flux ControlNet pipelines

• Add txt2img<->img2img<->inpaint automappings
• Correct image encoding dtype as VAE may not be the same as main model (typically its not when using quantized model)
• Add guidance handling to main txt pipeline (now inline with img2img and inpaint that already had this)

Closes #9398
Closes #9370

CC: @yiyixuxu @sayakpaul

[yiyixuxu]

thanks!

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

[vladmandic]

updated pipelines list to be sorted due to failing check.

[yiyixuxu]

@vladmandic
we have 2 commands that you can call to automatically format the code:make style and make quality - otherwise the CI wouldn't pass
just for future reference! I fixed the style already, will merge once the tests pass:)

[hervenivon]

Facing issues when using 'FluxMultiControlNetModel'.

A call to a pipeline leads to the following error: 'FluxMultiControlNetModel' object has no attribute 'config'

[hervenivon]

Facing issues when using 'FluxMultiControlNetModel'.

A call to a pipeline leads to the following error: 'FluxMultiControlNetModel' object has no attribute 'config'

For those stumbling upon this message.

A simple set of the config property does the trick:

base_model = 'black-forest-labs/FLUX.1-dev'
controlnet_model_union = 'InstantX/FLUX.1-dev-Controlnet-Union'

controlnet_union = FluxControlNetModel.from_pretrained(controlnet_model_union, torch_dtype=torch.bfloat16)
controlnet = FluxMultiControlNetModel([controlnet_union]) # we always recommend loading via FluxMultiControlNetModel

# Trick
controlnet.config = controlnet_union.config

pipe = FluxControlNetPipeline.from_pretrained(base_model, controlnet=controlnet, torch_dtype=torch.bfloat16)
pipe.to("cuda")

prompt = 'A bohemian-style female travel blogger with sun-kissed skin and messy beach waves.'
control_image_depth = load_image("https://huggingface.co/InstantX/FLUX.1-dev-Controlnet-Union/resolve/main/images/depth.jpg")
control_mode_depth = 2

control_image_canny = load_image("https://huggingface.co/InstantX/FLUX.1-dev-Controlnet-Union/resolve/main/images/canny.jpg")
control_mode_canny = 0

width, height = control_image.size

image = pipe(
    prompt, 
    control_image=[control_image_depth, control_image_canny],
    control_mode=[control_mode_depth, control_mode_canny],
    width=width,
    height=height,
    controlnet_conditioning_scale=[0.2, 0.4],
    num_inference_steps=24, 
    guidance_scale=3.5,
    generator=torch.manual_seed(42),
).images[0]