FindSWIG: Support swig4.0
SWIG 4.0 was released (https://sourceforge.net/p/swig/news/2019/04/swig-400-released/), current CMake module does not look for the swig4.0
name.
SWIG 4.0 was released (https://sourceforge.net/p/swig/news/2019/04/swig-400-released/), current CMake module does not look for the swig4.0
name.