Added theme, reworked UI

lib/repositories/account/models/category.dart

@@ -3,22 +3,30 @@ import 'dart:ui';
 class Category {
   String label;
   String color;
+  bool essential;
+  bool saving;
 
   Category({
     this.label = '',
     this.color = '',
+    this.essential = false,
+    this.saving = false,
   });
 
   factory Category.fromJson(Map<String, dynamic> json) {
     return Category(
       label: json['label'],
-      color: json['color']
+      color: json['color'],
+      essential: bool.parse(json['essential']),
+      saving: bool.parse(json['saving']),
     );
   }
 
   Map<String, String> toJson() => {
     'label': label,
     'color': color,
+    'essential': essential.toString(),
+    'saving': saving.toString(),
   };
 
   Color rgbToColor() {