Fixed sample.yaml

[zarifikram]

Key Problem : The sample.py expects args in a dictionary. instantiate_model_for_sample_mode() expects sample_mode_model_cfg as an arg. But current hydra config provides model_type, checkpoint_path, and denoise_path.

Other fixes :

• chunksize will be a part of design dict, previously was part of langevin.
• There was no dryrun arg before, now added.