Split MacOS binaries into amd64 and x64 versions to allow each to be shipped separately (feature request)

[eirikbakke]

The DuckDB JAR file is currently 73.3MB, which is a bit large for embedding into downloadable applications. Most of this comes from the four platform-dependent binaries inside:

• libduckdb_java.so_linux_amd64 (54.6MB)
• libduckdb_java.so_linux_arm64 (50.9MB)
• libduckdb_java.so_osx_universal (98.6MB)
• libduckdb_java.so_windows_amd64 (28.3MB)

It's easy enough to delete all of these but the one relevant to the architecture actually targeted in the bundle. But for the MacOS case, the arm64 and x64 binaries are combined into a single large "universal" executable. It would be helpful if the architectures were kept in separate files, so that only the relevant one could be included.