adding more typehints to DDIM scheduler (#456)
adding more typehints to DDIM scheduler (#456)

* adding more typehints

* resolving mypy issues

* resolving formatting issue

* fixing isort issue

Co-authored-by: V Vishnu Anirudh <1762be00ccd18152801bac377aa864d5eaaa40e2@gmail.com>
Co-authored-by: V Vishnu Anirudh <985d2b05e856c4de3ec66f786439e694692a2e2b@kth.se>
huggingface/diffusers