Function run 

pub fn run(
    package_source: &str,
    download_type: DownloadType,
    output_dir: Option<PathBuf>,
) -> Result<()>

Runs the download command to download a package archive or source bundle.

Errors

Returns an error if:

• The package cannot be resolved.
• The requested download type (Archive or Source) is not available for the package.
• The download fails or file system operations fail.