Add API for shuffling to MLContext

[BeanHsiang]

the class "TrainTestSplit" only support "Fraction" in TrainTestSplit.Input current, "Shuffle" is other important attribute.
Could ML.NET support "Shuffle & Split" next version?

[glebuk]

ApproximateBootstrapSampler should also do shuffle. Also there is a ShuffleTransform that can be added before the split. It will become available once we change the API in #371. Alternatively you can shuffle data prior to feeding it to ML.NET externally.

[Ivanidzo4ka]

DRI RESPONSE:
@Zruty0 do we plan to add Shuffle function to MlContext object?
Also probably worth to add sample of shuffling data into cookbook.

[Zruty0]

We do want to have shuffling available via MLContext, but not as an estimator/transformer. It'll be something like IDataView Shuffle(IDataView input, ....)

[shauheen]

@Ivanidzo4ka can you come up with a design?

[rogancarr]

I actually am working on this as part of the DataOperations catalog and just found this issue. I'll push a PR shortly.