#1164 CIF/BDD: Add BddUtils.printAsDot + some helper functions

Created the function printAsDot, and helper functions, in the class BddUtils to print a BDD in dot format where nodes directly mention its corresponding variable.

Before, a BDD could be printed in dot fromat using BDD.printDot, however this did not print the variable names in nodes as can be seen in this example:

Now, a BDD can be printed as:

We can see that the transformation is done correctly by looking at the variables and location pointers table:

Another example to showcase what happens when an extra variable set is used:

Closes #1164 (closed)