Implement Diffusion Policy on robomimic codebase

[caio-freitas]

Robomimic has some benchmarks for imitation learning from demonstrations that are used as a benchmark in DiffusionPolicy and other work.

• [x] Run training
• [x] Base code on robomimic library
• [ ] run Diffusion Policy on robomimic Algorithms Docs run_policy Notebook

Reference: Robomimic

[caio-freitas]

A RolloutPolicy has to be implemented for the DiffusionPolicy algorithm

[caio-freitas]

• [x] Config and Algo classes have to be written, to be added to the algorithm factory of robomimic, as in here.