Add method to close all invoices with an invoice direct

When the charge_members_manually option is active there is no need for an
explicit balancing step. This new function allows to close_direct all
orders which have an assigned invoice, which is usually indication enough
to find orders which can be closed finally.

app/views/finance/balancing/index.html.haml

@@ -1,3 +1,7 @@
 - title t('.title')
 
-#ordersTable= render 'orders'
+- content_for :actionbar do
+  - if FoodsoftConfig[:charge_members_manually]
+    = link_to t('.close_all_direct_with_invoice'), close_all_direct_with_invoice_finance_order_index_path, method: :post, class: 'btn'
+
+#ordersTable= render 'orders'