libsbml doesn't work with vckpg libraries

[luciansmith]

Moving from https://sourceforge.net/p/sbml/tickets/11/ :

"libsbml uses it's own library finding code in cmake. If this were changed to to use the standard built-in cmake find_package(...) routines, it would work out of the box with vcpkg libraries. This would make building on windows a lot easier."

(Reported by Andy Somogyi)