[IMP] point_of_sale: make the sequence field configurable

addons/point_of_sale/point_of_sale_view.xml

@@ -496,7 +496,7 @@
             <field name="field_parent" eval="False"/>
             <field name="arch" type="xml">
                 <tree string="Product Product Categories">
-                    <field name="sequence" invisible="1"/>
+                    <field name="sequence" widget="handle"/>
                     <field name="complete_name"/>
                 </tree>
             </field>