Add Monomorphism (in VF3L) and VF3P

Here are some changes that would enable monomorphism with VF3L (look-ahead does not work) and enable VF3P.

I feel like there should be some switches (or different function calls) on the Python side that allow the user to call either VF3, 3L or 3P, but I'm not very familiar with the Conan/pybind build system. Maybe the build script can be extended to build several different .so files?