stock_usability: clean-up zero-qty quants when opening quants from stock.location

When accessing stock.move.line from the show reservation on quants, in
the form view of stock.move.line, have a link to the picking

stock_usability/views/stock_location.xml

@@ -40,6 +40,10 @@
                 string="Reordering Rules"
                 class="oe_stat_button" icon="fa-refresh"/>
         </div>
+        <button name="%(stock.location_open_quants)d" position="attributes">
+            <attribute name="type">object</attribute>
+            <attribute name="name">action_show_quants</attribute>
+        </button>
     </field>
 </record>