small fixes for single payout and big chunck for multiple payouts

frontend/pweb/lib/controllers/payment_page.dart

@@ -0,0 +1,71 @@
+import 'package:flutter/foundation.dart';
+
+import 'package:pshared/provider/payment/flow.dart';
+import 'package:pshared/provider/payment/provider.dart';
+import 'package:pshared/provider/payment/quotation/quotation.dart';
+import 'package:pshared/provider/recipient/provider.dart';
+
+
+class PaymentPageController extends ChangeNotifier {
+  PaymentProvider? _payment;
+  QuotationProvider? _quotation;
+  PaymentFlowProvider? _flow;
+  RecipientsProvider? _recipients;
+
+  bool _isSending = false;
+  Exception? _error;
+
+  bool get isSending => _isSending;
+  Exception? get error => _error;
+
+  void update(
+    PaymentProvider payment,
+    QuotationProvider quotation,
+    PaymentFlowProvider flow,
+    RecipientsProvider recipients,
+  ) {
+    _payment = payment;
+    _quotation = quotation;
+    _flow = flow;
+    _recipients = recipients;
+  }
+
+  Future<bool> sendPayment() async {
+    if (_isSending) return false;
+    final payment = _payment;
+    if (payment == null) {
+      _setError(StateError('Payment provider is not ready'));
+      return false;
+    }
+
+    try {
+      _setSending(true);
+      _error = null;
+      final result = await payment.pay();
+      return result != null && payment.error == null;
+    } catch (e) {
+      _setError(e);
+      return false;
+    } finally {
+      _setSending(false);
+    }
+  }
+
+  void resetAfterSuccess() {
+    _quotation?.reset();
+    _payment?.reset();
+    _flow?.setManualPaymentData(null);
+    _recipients?.setCurrentObject(null);
+  }
+
+  void _setSending(bool value) {
+    if (_isSending == value) return;
+    _isSending = value;
+    notifyListeners();
+  }
+
+  void _setError(Object error) {
+    _error = error is Exception ? error : Exception(error.toString());
+    notifyListeners();
+  }
+}