[FEATURE] Add the AdEMAMix optimizer

[sarthakpati]

Is your feature request related to a problem? Please describe.

The AdEMAMix optimizer has been shown to work well for large models [ref].

Describe the solution you'd like

It would be great to make that available on GaNDLF.

Describe alternatives you've considered

N.A.

Additional context

There are a few implementations for torch:

• https://github.com/frgfm/Holocron/blob/main/holocron/optim/ademamix.py
• https://github.com/nanowell/AdEMAMix-Optimizer-Pytorch/blob/main/AdEMAMix.py
• https://github.com/riteshshergill/ademamix/blob/main/ademamix.py
• https://github.com/mcc5635/AdEMAMix-optimizer/blob/main/test.py#L6