one_hot_max_sizes: A torch tensor of dimension n_features containing the one hot sizes of the n_features
features. That is, if the ith feature is a categorical feature with 5 levels, then one_hot_max_sizes[i] = 5. While the size for continuous features can either be 0 or 1.
norm_mean: Torch tensor (optional). A 1D array containing the means of the columns of x_torch.
norm_std: Torch tensor (optional). A 1D array containing the stds of the columns of x_torch.
Returns
A list containing the normalized version of x_torch, norm_mean and norm_std.