Revisit CMake logic for creating Python extensions with pybind11

[kordejong]

On some platforms it is necessary to explicitly link to Python::Python, besides linking against pybind11::module. The docs suggest that linking against pybind11::module should be enough (https://pybind11.readthedocs.io/en/stable/compiling.html#advanced-interface-library-targets).

velocity and Saeb's computer, linking lue_py_framework_x fails. After linking against Python::Python it succeeds. Maybe something else is going on.