text: Title: Add the ability to test and sort timestamps to be monotonic in a pandas data frame
  Body: # Brief Description
  
  Following up on #703, this issue seeks to introduce the ability to sort the timestamps in a pandas data frame monotonically
  
  I would like to propose...
  
  # Example API
  ```python
  def _test_for_monotonicity(
          df: pd.DataFrame,
          column_name: str = None,
          direction: str = 'increasing'
  ) -> bool:
      """
      Tests input data frame for monotonicity.
  
      Check if the data is monotonically increasing or decreasing.
      Direction is dependent on user input.
      Defaults to increasing
  
      :param df: data frame to be tested for monotonicity
      :param column_name: needs to be specified if and only if the date time is not in index.
          Defaults to None.
      :param direction: specifies the direction in which monotonicity is being tested for.
          Defaults to 'increasing'
      :return: single boolean flag indicating whether the test has passed or not
      """
  
  def sort_monotonically(
          df: pd.DataFrame,
          column_name: str = None,
          direction: str ='increasing'
  ) -> pd.DataFrame:
      """
      Sorts data frame monotonically.
      It assumes the data frame has an index of type pd.DateTimeIndex when index is datetime.
      If datetime is in a column, then the column is expected to be of type pd.Timestamp
  
      :param df: data frame to sort monotonically
      :param column_name: needs to be specified if and only if the date time is not in index.
          Defaults to None
      :param direction: specifies the direction in which monotonicity is being tested for.
          Defaults to 'increasing'
      :return: data frame with its index sorted
      """
  
  
  # more examples below
  # ...
  ```
  