Made dataset the main container after load

src/main/java/seng202/group9/GUI/DatasetController.java

@@ -74,6 +74,7 @@ public class DatasetController extends Controller{
         Dataset datasetToOpen = (Dataset) datasetView.getSelectionModel().getSelectedItem();
         getParent().setCurrentDataset(datasetToOpen);
         loadTable();
+        getParent().getMenuController().replaceSceneContent(getParent().getSession().getSceneDisplayed());
         ((Stage) openDataset.getScene().getWindow()).close();
     }
 }