add set_checkbox_renderer

[WolfgangFahl]

def get_column_def(self,col:str)->Dict:
        """
        get the column definition for the given column

        Args:
            col (str): The field name of the column where checkboxes should be enabled.

        Returns:
            Dict: the column definition
        """

def set_checkbox_renderer(self,checkbox_col:str):
        """
        set cellRenderer to checkBoxRenderer for the given column

        Args:
            checkbox_col (str): The field name of the column where 
            rendering as checkboxes should be enabled.

        """