paramsView - a view of the full network (backprop) parameters
initializeParams - if true: initialize the parameters according to the configuration. If false: don't modify the
values in the paramsView array (but do select out the appropriate subset, reshape etc as required)
Map of parameters keyed by type (view of the 'paramsView' array)
Return a map of gradients (in their standard non-flattened representation), taken from the flattened (row vector) gradientView array.
The idea is that operates in exactly the same way as the the paramsView does in #init(Map, NeuralNetConfiguration, INDArray);
thus the position in the view (and, the array orders) must match those of the parameters