Update `BNNRegression` to support iterating over dataloader during `fit` similar to `BNNClassification`. https://github.com/IBM/UQ360/blob/main/uq360/algorithms/variational_bayesian_neural_networks/bnn.py#L54 https://github.com/IBM/UQ360/blob/main/uq360/algorithms/variational_bayesian_neural_networks/bnn.py#L216