StableDiffusion: Decode latents separately to run larger batches (#1150)
* StableDiffusion: Decode latents separately to run larger batches
* Move VAE sliced decode under enable_vae_sliced_decode and vae.enable_sliced_decode
* Rename sliced_decode to slicing
* fix whitespace
* fix quality check and repository consistency
* VAE slicing tests and documentation
* API doc hooks for VAE slicing
* reformat vae slicing tests
* Skip VAE slicing for one-image batches
* Documentation tweaks for VAE slicing
Co-authored-by: Ilmari Heikkinen <ilmari@fhtr.org>