[FIX] website_quote: set SO id in request

When a quotation is opened from the frontend, set the SO id in the
request. This is necessary in the following use case:
- Receive a website quote
- Pay thanks to Stripe

After commit da82a6b705, we call the route
`/shop/payment/transaction/` manually. However, this route expects to
retrieve the SO id thanks to a call to `sale_get_order`. Since we are
not going through the webshop and the user might not be connected, the
method is unable to retrieve the SO id.

opw-692341

addons/website_quote/controllers/main.py

@@ -30,6 +30,7 @@ class sale_quote(http.Controller):
 
         if not Order:
             return request.render('website.404')
+        request.session['sale_order_id'] = Order.id
 
         days = 0
         if Order.validity_date: