[FIX] website_sale: fix express checkout flow with extra_step

Before this commit, extra_info was never considered enabled since it was
checking the original view and not the current website view.

By default disabled, when you enable the view, multiwebsite duplicate this
view to enable it for the current website.

+ fix redirect to kanban adress after editing the billing address instead of
the step 'choose your shipping address'

task-1878245

addons/website_sale/controllers/main.py

@@ -664,7 +664,8 @@ class WebsiteSale(http.Controller):
                     order.partner_id = partner_id
                     order.onchange_partner_id()
                     if not kw.get('use_same'):
-                        kw['callback'] = kw.get('callback') or (not order.only_services and '/shop/address')
+                        kw['callback'] = kw.get('callback') or \
+                            (not order.only_services and (mode[0] == 'edit' and '/shop/checkout' or '/shop/address'))
                 elif mode[1] == 'shipping':
                     order.partner_shipping_id = partner_id
 
@@ -709,7 +710,6 @@ class WebsiteSale(http.Controller):
         if post.get('express'):
             return request.redirect('/shop/confirm_order')
 
-
         values.update({'website_sale_order': order})
 
         # Avoid useless rendering if called in ajax
@@ -725,14 +725,13 @@ class WebsiteSale(http.Controller):
         if redirection:
             return redirection
 
-
         order.onchange_partner_shipping_id()
         order.order_line._compute_tax_id()
         request.session['sale_last_order_id'] = order.id
         request.website.sale_get_order(update_pricelist=True)
         extra_step = request.env.ref('website_sale.extra_info_option')
         if extra_step.active:
-            return request.redirect("/shop/extra_info")
+            return request.redirect("/shop/confirm_order")
 
         return request.redirect("/shop/payment")
 
@@ -741,9 +740,8 @@ class WebsiteSale(http.Controller):
     # ------------------------------------------------------
     @http.route(['/shop/extra_info'], type='http', auth="public", website=True)
     def extra_info(self, **post):
-
         # Check that this option is activated
-        extra_step = request.env.ref('website_sale.extra_info_option')
+        extra_step = request.env['ir.ui.view']._view_obj('website_sale.extra_info_option')  # ref but specific
         if not extra_step.active:
             return request.redirect("/shop/payment")