was UltraGrid-<arch>-<version>.dmg (eg. UltraGrid-arm64-1.9.2.dmg),
which is not consistent with other platforms,
eg. UltraGrid-1.9.2-x86_64.AppImage and UltraGrid-1.9.2-win64.zip. The
one with the version just after UltraGrid seems to be more natural.
the former was a bit error-prone and eg. since 2b9ed6c7 (2023-05-15),
icon.icns was not copied (just to old bundle but not re-copied to GUI
bundle). Also things like Vulcan shaderes were not copied.
Here, we use a no-clobber option not to override files specific to GUI
bundle.
+ fixed the actaull path of icon.icns inside the bundle
