message: Reuse `PaneGrid::focus` to remove some duplication
diff: @@ -449,10 +449,7 @@ impl<T> State<T> {
  node.split(kind, new_pane);
  let _ = self.panes.insert(new_pane, state);
  - self.internal.focused_pane = FocusedPane::Some {
  - pane: new_pane,
  - focus: Focus::Idle,
  - };
  + self.focus(&new_pane);
  Some(new_pane)
  }
  @@ -472,11 +469,7 @@ impl<T> State<T> {
  pub fn close(&mut self, pane: &Pane) -> Option<T> {
  if let Some(sibling) = self.internal.layout.remove(pane) {
  - self.internal.focused_pane = FocusedPane::Some {
  - pane: sibling,
  - focus: Focus::Idle,
  - };
  -
  + self.focus(&sibling);
  self.panes.remove(pane)
  } else {
  None
  