Dgenerate

* `--scheduler`, `--sdxl-refiner-scheduler`, and `--s-cascade-decoder-scheduler` can now handle being passed multiple URIs, this allows you to iterate over different schedulers (samplers) directly from the CLI with one command and no further scripting. These arguments now also have pluralized aliases: `--schedulers`, `--sdxl-refiner-schedulers`, and `--s-cascade-decoder-schedulers`, to help with potentially annoying typos. Using multiple schedulers contributes to generation steps combinatorically, in the same way as other diffusion parameter arguments such as `--inference-steps` and `--guidance-scales` etc.

* New `Edit -> Insert Argument` Console UI dialog, you can now select dgenerate arguments from a drop down and insert them into the config. This new dialog has a help button which will display the help text for the selected argument from dgenerates `--help` output in isolation, similar to the help window available in the image processor selection UI. This dialog is also available by right clicking the text input area in the Console UI and selecting `Insert Argument`.

* `--pag-scales`, `--pag-adaptive-scales`, `--sdxl-refiner-pag-scales`, and `--sdxl-refiner-pag-adaptive-scales` are now properly reproduced in configuration produced by `--output-configs`. Previously they were left un-pluralized (typo)

* `--help` text information fix under `--text-encoders`. Model type keyword `T5TextModel` corrected to `T5EncoderModel`.

* Fix for user configurable environmental variable `DGENERATE_WEB_CACHE_EXPIRY_DELTA`, setting value to `forever` no longer
triggers a datetime overflow. `DGENERATE_WEB_CACHE_EXPIRY_DELTA=forever` should retain files downloaded to dgenerates
cache forever, this cache is unrelated to the cache in `HF_HOME`, and is used for models / files downloaded from locations other than huggingface.

Iterate over any scheduler options

\setp schedulers [ \
'EulerAncestralDiscreteScheduler', \
'KDPM2AncestralDiscreteScheduler', \
'EulerDiscreteScheduler', \
'KDPM2DiscreteScheduler', \
'HeunDiscreteScheduler']

{% for scheduler in schedulers %}
stabilityai/stable-diffusion-xl-base-1.0
--model-type torch-sdxl
--dtype float16
--variant fp16
--scheduler {{ scheduler }}
--model-cpu-offload
--prompts "add your prompt here"
{% endfor %} !END


Issue only occurred with `--model-cpu-offload/--model-sequential-offload` enabled due to quirks with `accelerate` offloading and high memory usage.

Include transient dependency `bitsandbytes` on Windows and Linux for loading quantized weights.

Documentation and `--help` output fixes.

* Flux img2img, inpainting, and Control Net support. `InstantX/FLUX.1-dev-Controlnet-Union` is also supported with `--model-type torch-flux` via a `mode` URI argument to `--control-nets`, see: [Flux Union Control Net Mode](https://github.com/Teriks/dgenerate/tree/master?tab=readme-ov-file#flux-union-control-net-mode) in the README.

* PAG perturbed attention guidance support for Stable Diffusion, SDXL, and SD3, see: [Feature Table](https://github.com/Teriks/dgenerate/blob/master/FEATURE_TABLE.rst#pag-support-caveats) for support caveats. New arguments have been added for working with PAG: `--pag`, `--pag-scales`, `--pag-adaptive-scales`, `--sdxl-refiner-pag`, `--sdxl-refiner-pag-scales`, and `--sdxl-refiner-pag-adaptive-scales`.

* Console UI recipe form updates for Flux control nets, added basic UI for specifying one control net model, control net scale, and control net mode for Flux ControlNet Union.