Kliff master v1 lightning

[ipcamit]

Summary

Added base trainer and lightning trainer. Along with new tests to test the trainer module

Additional dependencies introduced (if any)

• torch lightning for lightning trainer in ["test"]

TODO (if any)

Add KIM Trainer next

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[mjwen]

@ipcamit Nothing major, but a few clarifying questions and minor tweaks.

[ipcamit]

Addressed most comments. Need some more time and meeting with Josh for Loss trajectory concretization. Will address the descriptor dataloader issues with torch trainer which uses the descriptor module, so it will be easier to see the design choices.