Add Prodigy optimizer

[swfsql]

This is a request to add the Prodigy optimizer - reference pytorch implementation.

I think this could be helpful for newcomers as they presumably would have to bother less with manually setting optimizer configs.

[swfsql]

Closing as I did not have success in getting benefit from the implementation, which may be wrong.

But feel free to ping or re-open in case anyone has an interest!