More refactoring of library common for path uploads.
Refactor get_server_dir_uploaded_datasets to separate logic out for listing files.
Implement creating multiple file datasets through library contents api from file system paths.
Implement creating multfifile from server upload in library_common.py.
Fixup server multifile upload api call.
Add multifile upload via paths to api.
Fixes for _get_path_files_and_folders
Fixes for get_server_dir_multifile_uploaded_datasets
Fixes for get_path_paste_multifile_uploaded_datasets