I'd like to be able to easily and persistently store EvalOutput results to e.g. local disk or NoSQL databases like DynamoDB... And ideally also load them back into fmeval/Python objects.

There are several good reasons why I'd prefer to avoid just using pickle... and JSON seems like a natural fit for this kind of data, but we can't simply json.dumps() an EvalOutput object today.

It would be useful if we offered a clear mechanism to save the evaluation summary/scores to JSON, and ideally load back from JSON as well.