input: Write a python function to get the default language name from settings and return it as a unicode string.
  ```python
  assert get_default_language_name() == 'English'
output: def get_default_language_name():
      settings = {
          'default_language': 'en',
          'languages': {
              'en': 'English',
              'es': 'Spanish',
              'fr': 'French'
          }
      }
      default_language_code = settings['default_language']
      return settings['languages'][default_language_code]