message: Remove unnecesary use of `Option::unwrap`
  ... in `overlay` implementation for `pane_grid::TitleBar`
diff: @@ -249,10 +249,10 @@ where
  layout: Layout<'_>,
  ) -> Option<overlay::Element<'_, Message, Renderer>> {
  let mut children = layout.children();
  - let padded = children.next().unwrap();
  + let padded = children.next()?;
  let mut children = padded.children();
  - let title_layout = children.next().unwrap();
  + let title_layout = children.next()?;
  let Self {
  content, controls, ..
  @@ -260,7 +260,7 @@ where
  content.overlay(title_layout).or_else(move || {
  controls.as_mut().and_then(|controls| {
  - let controls_layout = children.next().unwrap();
  + let controls_layout = children.next()?;
  controls.overlay(controls_layout)
  })
  