message: persist whether the filter is open as part of the saved layout
diff: @@ -4572,6 +4572,7 @@ QVariant EventBrowser::persistData()
  ui->events->header()->setStretchLastSection(true);
  state[lit("columns")] = columns;
  + state[lit("filterVisible")] = ui->filter->isChecked();
  return state;
  }
  @@ -4597,6 +4598,8 @@ void EventBrowser::setPersistData(const QVariant &persistData)
  else
  ui->events->header()->showSection(i);
  }
  +
  + ui->filter->setChecked(state[lit("filterVisible")].toBool());
  }
  void EventBrowser::events_keyPress(QKeyEvent *event)
  