Add "Reshape Transform"

We need the following functionalities in order to score TensorFlow models:

1. Change the ColumnType of the column to be a different shape – this would not do anything to the data, it would just change the type of the column, to match the input dimensions the model expects (for example, if the data contains a column of length 784, and the model expects a 28x28 input).
2. Actually reshape the data – (C,H,W) to (H,W,C). This transform would also have to move data around in addition to changing the ColumnType.
3. Reshape data from RGB to other ordering of the channels. This transform would move the data around, but leave the ColumnType as it was.

2 is already implemented as an option in the PixelExtractorTransform, and 3 could also be implemented as an option in that transform, but it may be useful to have them as a separate transform, for cases where the input data doesn't necessarily come from the PixelExtractorTransform.