Windows support of external libraries.

Currently, the cmake build disable a bunch of interfaces that do not compile on windows CI (c.f. the python PR workflow). This is not a multipers issue per se, but I'll track that here

• mpfree
• function_delaunay
• multi_critical
• rhomboid_tiling
• hera

Relevant block of code in cmake/MultipersBuild.cmake:

  if(WIN32)
    target_compile_definitions(
      ${target_name}
      PRIVATE
        MULTIPERS_DISABLE_MPFREE_INTERFACE=1
        MULTIPERS_DISABLE_FUNCTION_DELAUNAY_INTERFACE=1
        MULTIPERS_DISABLE_MULTI_CRITICAL_INTERFACE=1
        MULTIPERS_DISABLE_RHOMBOID_TILING_INTERFACE=1
        MULTIPERS_DISABLE_HERA_INTERFACE=1,
    )
  endif()

I don't have access to a windows machine, so I won't touch that for the moment. Feel free to look at it if you have a windows machine.