What: This class adds a generic BatchPredictor class that offers an interface to run batch inference on Ray datasets. It takes a Predictor class and checkpoint as an input, and provides a predict(dataset) method to run scalable scoring inference.
Why: Currently users have to implement scorers themselves. This is mostly boilerplate and prone to errors, so we should provide a simple solution instead.
Note that this predictor also implements the Predictor interface.
