yoda: warning cleanup sweep (dead code + clippy --fix) (squashed)

Squash of 4 yoda commits:
- 84437e21 yoda: libcosmic-yoda dead-code purge (14->0 warnings)
- 999db0a4 yoda: cosmic-theme cleanup (4->0 warnings) — workspace at 0 warnings total
- 4743bb8e yoda: cargo clippy --fix on libcosmic-yoda (115->33 warnings)
- 675f3b59 chore: reduce local stack warnings

src/widget/menu/menu_bar.rs

@@ -50,7 +50,6 @@ pub(crate) struct MenuBarStateInner {
     pub(crate) tree: Tree,
     pub(crate) popup_id: HashMap<window::Id, window::Id>,
     pub(crate) pressed: bool,
-    pub(crate) bar_pressed: bool,
     pub(crate) view_cursor: Cursor,
     pub(crate) open: bool,
     pub(crate) active_root: Vec<usize>,
@@ -87,7 +86,6 @@ impl Default for MenuBarStateInner {
             vertical_direction: Direction::Positive,
             menu_states: Vec::new(),
             popup_id: HashMap::new(),
-            bar_pressed: false,
         }
     }
 }
@@ -164,14 +162,6 @@ where
     }
 }
 
-pub fn get_mut_or_default<T: Default>(vec: &mut Vec<T>, index: usize) -> &mut T {
-    if index < vec.len() {
-        &mut vec[index]
-    } else {
-        vec.resize_with(index + 1, T::default);
-        &mut vec[index]
-    }
-}
 
 /// A `MenuBar` collects `MenuTree`s and handles all the layout, event processing, and drawing.
 #[allow(missing_debug_implementations)]
@@ -622,14 +612,12 @@ where
                 .with_data(|d| !d.open && !d.active_root.is_empty());
 
         let open = my_state.inner.with_data_mut(|state| {
-            if reset {
-                if let Some(popup_id) = state.popup_id.get(&self.window_id).copied() {
-                    if let Some(handler) = self.on_surface_action.as_ref() {
+            if reset
+                && let Some(popup_id) = state.popup_id.get(&self.window_id).copied()
+                    && let Some(handler) = self.on_surface_action.as_ref() {
                         shell.publish((handler)(crate::surface::Action::DestroyPopup(popup_id)));
                         state.reset();
                     }
-                }
-            }
             state.open
         });