fix(neon,neon_notes): properly dispose FocusNodes

Signed-off-by: Nikolas Rimikis <leptopoda@users.noreply.github.com>

packages/neon/neon/lib/src/widgets/app_bar.dart

@@ -55,6 +55,7 @@ class _NeonAppBarState extends State<NeonAppBar> {
 
   @override
   void dispose() {
+    _searchBarFocusNode.dispose();
     unawaited(_searchTermSubscription.cancel());
     unawaited(_searchTermController.close());
     super.dispose();

packages/neon/neon_notes/lib/pages/note.dart

@@ -61,6 +61,8 @@ class _NotesNotePageState extends State<NotesNotePage> {
   void dispose() {
     _contentController.dispose();
     _titleController.dispose();
+    _contentFocusNode.dispose();
+    _titleFocusNode.dispose();
     unawaited(_contentStreamController.close());
     unawaited(_titleStreamController.close());
     super.dispose();