Display the list of expenses

moneymgr_mobile/lib/services/storage/expenses.dart

@@ -16,7 +16,7 @@ typedef ExpensesList = List<Expense>;
 @freezed
 abstract class BaseExpenseInfo with _$BaseExpenseInfo {
   const factory BaseExpenseInfo({
-    required String label,
+    required String? label,
     required double cost,
     required DateTime time,
   }) = _BaseExpenseInfo;
@@ -53,6 +53,12 @@ abstract class Expense with _$Expense {
     if (mimeType == "image/png") return "$id.png";
     return id.toString();
   }
+
+  /// Get expense label or null if empty
+  String? get labelOrNull => label == "" ? null : label;
+
+  /// Get expense date
+  DateTime get dateTime => DateTime.fromMillisecondsSinceEpoch(time * 1000);
 }
 
 @riverpod