stacked bar graph, edit / remove transaction & budget page base

lib/repositories/account/models/transaction.dart

@@ -1,4 +1,7 @@
+import 'package:uuid/uuid.dart';
+
 class Transaction {
+  String uuid;
   DateTime date;
   String category;
   String description;
@@ -6,6 +9,7 @@ class Transaction {
   double value;
 
   Transaction({
+    required this.uuid,
     required this.date,
     required this.category,
     required this.description,
@@ -15,6 +19,7 @@ class Transaction {
 
   factory Transaction.fromJson(Map<String, dynamic> json) {
     return Transaction(
+      uuid: json['uuid'] ?? const Uuid().v8(),
       date: DateTime.parse(json['date']),
       category: json['category'],
       description: json['description'],
@@ -24,6 +29,7 @@ class Transaction {
   }
 
   Map<String, String> toJson() => {
+    'uuid': uuid,
     'date': date.toIso8601String(),
     'category': category,
     'description': description,