[FIX] sale, portal_sale: hide buttons for portal users

When a portal user opened his quotation form,
all buttons of the regular form were available.

They were not working, due the access rights,
but it's better to hide them.

opw-657654

addons/portal_sale/portal_sale_view.xml

@@ -20,6 +20,9 @@
             <field name="groups_id" eval="[(4, ref('base.group_portal'))]"/>
             <field name="arch" type="xml">
                 <data>
+                    <header position="replace">
+                        <field name="state" invisible="1"/>
+                    </header>
                     <xpath expr='//field[@name="order_line"]/form//field[@name="procurement_ids"]' position="replace"/>
                     <xpath expr='//field[@name="order_line"]/form//field[@name="product_id"]' position="replace"/>
                     <xpath expr='//field[@name="order_line"]/form//field[@name="qty_delivered_updateable"]' position="replace"/>

addons/sale/wizard/sale_make_invoice_advance.xml

@@ -47,6 +47,7 @@
             <field name="view_type">form</field>
             <field name="view_mode">form</field>
             <field name="target">new</field>
+            <field name="groups_id" eval="[(4,ref('base.group_sale_salesman'))]"/>
         </record>
 
         <!-- TODO: check if we need this -->