style(neon_notes): cleanup NotesCategorySelect

packages/neon/neon_notes/lib/widgets/category_select.dart

@@ -11,6 +11,13 @@ class NotesCategorySelect extends StatelessWidget {
     if (initialValue != null) {
       onChanged(initialValue!);
     }
+
+    categories.sort();
+
+    // After sorting the empty category '' should be at the first place
+    if (!categories.first.isNotEmpty) {
+      categories.insert(0, '');
+    }
   }
 
   final List<String> categories;
@@ -18,8 +25,6 @@ class NotesCategorySelect extends StatelessWidget {
   final Function(String category) onChanged;
   final Function() onSubmitted;
 
-  late final _categories = categories..sort((final a, final b) => a.compareTo(b));
-
   @override
   Widget build(final BuildContext context) => Autocomplete<String>(
         initialValue: initialValue != null
@@ -28,13 +33,6 @@ class NotesCategorySelect extends StatelessWidget {
               )
             : null,
         optionsBuilder: (final value) {
-          final categories = [
-            if (!_categories.contains('')) ...{
-              '',
-            },
-            ..._categories,
-          ];
-
           if (value.text.isEmpty) {
             return categories;
           }