feat: update the headerbar to match figma

i don't think the alpha is actually working for the icon, but the color should match

src/widget/nav_bar_toggle.rs

@@ -13,6 +13,8 @@ pub struct NavBarToggle<Message> {
     active: bool,
     #[setters(strip_option)]
     on_toggle: Option<Message>,
+    style: crate::theme::Button,
+    selected: bool,
 }
 
 #[must_use]
@@ -20,6 +22,8 @@ pub fn nav_bar_toggle<Message>() -> NavBarToggle<Message> {
     NavBarToggle {
         active: false,
         on_toggle: None,
+        style: crate::theme::Button::Text,
+        selected: false,
     }
 }
 
@@ -37,10 +41,11 @@ impl<'a, Message: 'static + Clone> From<NavBarToggle<Message>> for Element<'a, M
             .symbolic(true)
         };
 
-        widget::button::text("")
-            .leading_icon(icon)
+        widget::button::icon(icon)
             .padding([8, 16, 8, 16])
             .on_press_maybe(nav_bar_toggle.on_toggle)
+            .selected(nav_bar_toggle.selected)
+            .style(nav_bar_toggle.style)
             .apply(widget::container)
             .center_y()
             .height(Length::Fill)