Frontend first draft

frontend/pshared/lib/utils/currency.dart

@@ -0,0 +1,22 @@
+String currencyCodeToSymbol(String currencyCode) {
+  switch (currencyCode) {
+    case 'USD':
+      return '\$';
+    case 'PLN':
+      return 'zł';
+    case 'EUR':
+      return '€';
+    case 'GBP':
+      return '£';
+    case 'HUF':
+      return 'Ft';
+    case 'RUB':
+      return '₽';
+    default:
+      return currencyCode;
+  }
+}
+
+String currencyToString(String currencyCode, double amount) {
+  return '${currencyCodeToSymbol(currencyCode)}\u00A0${amount.toStringAsFixed(2)}';
+}