This should improve the signing process of Mac Applications.
This improves the frameworks of external dependencies used by SFML. To
patch sfml-*.framework, one would need to customised the
`MACOSX_FRAMEWORK_INFO_PLIST` cmake property and provide a custom
Info.plist file with CFBundleSupportedPlatforms property set. See
https://cmake.org/cmake/help/latest/prop_tgt/FRAMEWORK.html
This is however not required (probably) if one used dylibs instead.
Related to #1020 and #1036. Credits go to @kipbits.
