Allow to create invoices before bank transfer runs (#1734)

Co-authored-by: Raphael Michel <michel@rami.io>

src/pretix/plugins/banktransfer/payment.py

@@ -98,6 +98,12 @@ class BankTransfer(BasePaymentProvider):
                 }},
                 required=False
             )),
+            ('invoice_immediately',
+             forms.BooleanField(
+                 label=_('Create an invoice for orders using bank transfer immediately if the event is otherwise '
+                         'configured to create invoices after payment is completed.'),
+                 required=False,
+             )),
             ('public_name', I18nFormField(
                 label=_('Payment method name'),
                 widget=I18nTextInput,
@@ -119,6 +125,10 @@ class BankTransfer(BasePaymentProvider):
         return _('In test mode, you can just manually mark this order as paid in the backend after it has been '
                  'created.')
 
+    @property
+    def requires_invoice_immediately(self):
+        return self.settings.get('invoice_immediately', False, as_type=bool)
+
     @property
     def settings_form_fields(self):
         d = OrderedDict(list(super().settings_form_fields.items()) + list(BankTransfer.form_fields().items()))