[FIX] stock : webplanner link to product does not work.

In the planner the url are generated by prepare_backend_url that takes
an action's xml id as argument. The id passed should have the format
'module_name_where_the_action_is.action_name'. In this case the id passed
was product.product_template_action_product but the action is defined in
stock thus the prepare_backend_url was not able to find the associate action
and return a wrong(default) url.

This commit change the action id passed with the correct module.

closes odoo/odoo#18812

Signed-off-by: Arnold Moyaux <amoyaux@users.noreply.github.com>

addons/stock/data/web_planner_data.xml

@@ -226,7 +226,7 @@
                                     </p>
                                     <ul>
                                         <li>Download the <a href="/base_import/static/csv/products.xls">Excel template</a></li>
-                                        <li>Import using the top left button in <a t-att-href="prepare_backend_url('product.product_template_action_product','list')">the list of products</a></li>
+                                        <li>Import using the top left button in <a t-att-href="prepare_backend_url('stock.product_template_action_product','list')">the list of products</a></li>
                                     </ul>
                                 </div>
                             </div>
@@ -375,7 +375,7 @@
                         running out of stock.
                     </p>
                     <p>
-                        To create them, click on <strong><span class="fa fa-refresh"/> Reordering</strong> on <a t-att-href="prepare_backend_url('product.product_template_action_product')">a stockable Product</a> and simply enter a minimum and maximum quantity.
+                        To create them, click on <strong><span class="fa fa-refresh"/> Reordering</strong> on <a t-att-href="prepare_backend_url('stock.product_template_action_product')">a stockable Product</a> and simply enter a minimum and maximum quantity.
                     </p>
                 </t>