Support ROBOTOLOGY_USES_OCTAVE on Windows

[traversaro]

This wil probably require some modifications to https://github.com/robotology/ycm/blob/7cc2b755e302b972112ca6b77a6dbce4492d0062/3rdparty/cmake-wiki/FindOctave.cmake .

[traversaro]

This requires much more then just tweaking the FindOctave.cmake . As of early 2020, Octave plugins use a C++ API to talk to the Octave core libraries, and the default binaries of Octave are compiled with mingw-w64, a compiler toolchain that uses a different C++ ABI (in particular a different mangling) w.r.t. to the MSVC based toolchain that we support on Windows. As far as I know, at the moment it is not possible to compile Octave to have a MSVC-compatible ABI.

To support Octave on Windows, we should support compiling the superbuild (and its dependencies) on Windows against mingw-w64. This may be doable (especially now that vcpkg support mingw-w64 triplets, see microsoft/vcpkg#9137), but it is not planned for the future. For the moment I would just document that ROBOTOLOGY_USES_OCTAVE is not supported on Windows, and link to this issue for further explanation. If someone is interested in getting ROBOTOLOGY_USES_OCTAVE to work on Windows, feel free to comment on this issue so that we can re-open it.