Работает функционал переключения валют, остались правки по ui

lib/db.dart

@@ -114,9 +114,15 @@ class SqliteHelper {
     return locale;
   }
 
-  Future<String> getCurrency() async {
+  Future<int> getCurrency() async {
     Map settings = await selectAll(tableSettings);
-    String currency = settings != null ? settings[columnCurrency] : null;
+    int currency = settings != null ? settings[columnCurrency] : null;
+    print('currency: {$currency}');
+    return currency;
+  }
+
+  Future<int> saveCurrency(int currency) async {
+    db.update(tableSettings, {columnCurrency: currency});
     print('currency: {$currency}');
     return currency;
   }