Add consumer<int> overload for bdd_satmin and bdd_satmax

[SSoelvsten]

As a follow-up on #225 in conjunction with #556, the bdd_satmin and bdd_satmax should be overloaded with a consumer<int> where the signedness is used to reflect negation (potentially with an exception if zero is assigned anything?).

• bdd_satmin(f, consumer<int>) and add unit tests
• bdd_satmax(f, consumer<int>) and add unit tests
• Add unit tests to check the iterator-based overloads work as expected with a std::vector<int> buffer.