input: Write a python function to get the proposed new path for an archive if it's renamed after a directory.
  assert get_new_file_path("/path/to/file.zip", "dir-name") == "/path/to/dir-name.zip"
  assert get_new_file_path("/another/path/to/file.rar", "archive-name") == "/another/path/to/archive-name.rar"
  assert get_new_file_path("/singlefile", "new-singlefile") == "/new-singlefile"
output: def get_new_file_path(current_path, new_dir_name):
      import os
      directory, filename = os.path.split(current_path)
      new_filename = f"{new_dir_name}{os.path.splitext(filename)[1]}"
      return os.path.join(directory, new_filename)