kakaobrain unCLIP (#1428)
* [wip] attention block updates
* [wip] unCLIP unet decoder and super res
* [wip] unCLIP prior transformer
* [wip] scheduler changes
* [wip] text proj utility class
* [wip] UnCLIPPipeline
* [wip] kakaobrain unCLIP convert script
* [unCLIP pipeline] fixes re: @patrickvonplaten
remove callbacks
move denoising loops into call function
* UNCLIPScheduler re: @patrickvonplaten
Revert changes to DDPMScheduler. Make UNCLIPScheduler, a modified
DDPM scheduler with changes to support karlo
* mask -> attention_mask re: @patrickvonplaten
* [DDPMScheduler] remove leftover change
* [docs] PriorTransformer
* [docs] UNet2DConditionModel and UNet2DModel
* [nit] UNCLIPScheduler -> UnCLIPScheduler
matches existing unclip naming better
* [docs] SchedulingUnCLIP
* [docs] UnCLIPTextProjModel
* refactor
* finish licenses
* rename all to attention_mask and prep in models
* more renaming
* don't expose unused configs
* final renaming fixes
* remove x attn mask when not necessary
* configure kakao script to use new class embedding config
* fix copies
* [tests] UnCLIPScheduler
* finish x attn
* finish
* remove more
* rename condition blocks
* clean more
* Apply suggestions from code review
* up
* fix
* [tests] UnCLIPPipelineFastTests
* remove unused imports
* [tests] UnCLIPPipelineIntegrationTests
* correct
* make style
Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>
