[FIX] stock_account: display to_refund on return picking as toggle

When clicking on a stock.picking form
a modal appeared,

Before this commit a checkbox on the lines was present to update the PO
Since one needed to click on span to put the line in edit mode and edit the boolean
It seemed that the boolean was not editable.

After this commit, we add the toggle_boolean widget to handle the field
It is interactive even if the line is not in edit mode.

OPW 1818700
closes #24138

addons/stock_account/views/stock_account_views.xml

@@ -44,7 +44,7 @@
             <field name="model">stock.return.picking</field>
             <field name="arch" type="xml">
                 <xpath expr="//field[@name='product_return_moves']/tree" position="inside">
-                    <field name="to_refund"/>
+                    <field name="to_refund" widget="boolean_toggle"/>
                 </xpath>
             </field>
         </record>