basic csv loader, transaction list & half done stats page

lib/domains/account/models/transaction_category.dart

@@ -0,0 +1,19 @@
+import 'package:formz/formz.dart';
+
+enum TransactionCategoryValidationError {
+  empty('Category empty'),
+  invalid('Category invalid');
+
+  final String message;
+  const TransactionCategoryValidationError(this.message);
+}
+
+class TransactionCategory extends FormzInput<String, TransactionCategoryValidationError> {
+  const TransactionCategory.pure() : super.pure('');
+  const TransactionCategory.dirty([super.value = '']) : super.dirty();
+
+  @override
+  TransactionCategoryValidationError? validator(String value) {
+    return value.isEmpty ? TransactionCategoryValidationError.empty : null;
+  }
+}