[tf.data] Introducing `tf.data.Dataset.window(size, shift, stride,...

[tf.data] Introducing `tf.data.Dataset.window(size, shift, stride, drop_remainder)`, which can be used for combining elements of input dataset into "windows". A window
is itself a finite dataset and, among other things, can be used for generalized batching (see https://github.com/tensorflow/community/pull/5 for details).

PiperOrigin-RevId: 213360134