remove plotting functions from Dataset func

src/Dataset.py

@@ -75,15 +75,6 @@ class Dataset:
         """
         return self.dataframe
 
-    def draw_histogram(self):
-        raise NotImplementedError
-
-    def get_dataset_columns(self) -> list:
-        return self.dataframe.columns
-
-    def get_plottable_columns(self) -> list:
-        raise NotImplementedError
-
     def get_sorted_column(
         self, colname: str, ascending: bool = True
     ) -> pd.Series: