plot_dynamic_network: Plots a dynamic Bayesian network in a hierarchical way
Description
To plot the DBN, this method first computes a hierarchical structure
for a time slice and replicates it for each slice. Then, it calculates the
relative position of each node with respect to his equivalent in the first
slice. The result is a net where each time slice is ordered and separated
from one another, where the leftmost slice is the oldest and the rightmost
represents the present time.