Convert Libsvm records to a tensor of label and a tensor of feature.

content A Tensor of type string. Each string is a record/row in the Libsvm format.
num_features The number of features.
dtype The type of the output feature tensor. Default to tf.float32.
label_dtype The type of the output label tensor. Default to tf.int64.

features A SparseTensor of the shape [input_shape, num_features].
labels A Tensor of the same shape as content.