Copies the whole content of a DSS folder to a local path
dkuDownloadProjectLibraries(project_key, local_base_path, subpath = NULL)
the local path (directory) to download to. If this path does not exist, it is created.
Files that are both in the source and destination are overwritten. Files that exist in the destination but not in the DSS folder are preserved
the id of the DSS folder