MG End-to-end example

[jasonlyik]

Add end-to-end flow for MackeyGlass, including dataloader, model, Benchmark, metrics interface but no calculation yet.

[jasonlyik]

branch is called kws-example but completed the MG example

[EssentiallyNoah]

@jasonlyik Would it be possible to break this out into a couple different pull requests? Just so it's a little more traceable down the line