* cosmos predict2.5 base: convert chkpt & pipeline
- New scheduler: scheduling_flow_unipc_multistep.py
- Changes to TransformerCosmos for text embeddings via crossattn_proj
* scheduler cleanup
* simplify inference pipeline
* cleanup scheduler + tests
* Basic tests for flow unipc
* working b2b inference
* Rename everything
* Tests for pipeline present, but not working (predict2 also not working)
* docstring update
* wrapper pipelines + make style
* remove unnecessary files
* UniPCMultistep: support use_karras_sigmas=True and use_flow_sigmas=True
* use UniPCMultistepScheduler + fix tests for pipeline
* Remove FlowUniPCMultistepScheduler
* UniPCMultistepScheduler for use_flow_sigmas=True & use_karras_sigmas=True
* num_inference_steps=36 due to bug in scheduler used by predict2.5
* Address comments
* make style + make fix-copies
* fix tests + remove references to old pipelines
* address comments
* add revision in from_pretrained call
* fix tests