MacOS fixes + troubleshooting documentation

[LucindaLanoy]

This PR brings the following changes :

• for macOS, a symlink was created to fix the bug that made the program look for OpenCvSharpExtern.dylib instead of the real file libOpenCvSharpExtern.dylib,
• the @executable_path/../libs bug on macOS can't be fixed during the release built, in consequence the documentation has been updated with the command needed to fix this behaviour locally,
• the documentation was also updated with trouleshooting on possible issues on Linux (dependencies + GC)
• added a sample cyz file to make the check workflow test for conversion as well in addition to the build of the program, a readme will be added later with information on the file itself.