Signing Windows macOS binaries

1. Request / retrieve signing certificate (e.g. from DTU)

2. Add the CERT to Windows / macOS

3. Build the binaries

4. Signing on Windows:

signtool sign /a /fd sha256 McStas-Metapackage-3.1-win64.exe

5. Signing on macOS:

codesign -s "Danmarks Tekniske Universitet" "/Applications/McStas-3.1.app" --deep