[FIX] contract: portal contract page crashes on sale-order JS interaction

Opening a contract in the portal raised a client-side TypeError:

    can't access property "dataset", this.el.querySelector(...) is null
    at SaleUpdateLineButton.setup()

The portal_contract_page template used the wrapper class
"o_portal_sale_sidebar", which is the binding selector for the sale and
sale_management frontend interactions (SaleSidebar, SaleUpdateLineButton,
PortalPrepayment). SaleUpdateLineButton.setup() runs
`this.el.querySelector("table#sales_order_table").dataset`, which is null
on a contract page (no sale-order table) -> the whole interaction bundle
throws and the page errors.

The contract portal page needs no JS interaction, so switch to the neutral
"o_portal_sidebar" class. Layout is pure bootstrap grid and is unaffected.

Introduced by the portal contract page redesign (bbf9fa8).

Author: bosd

contract/__manifest__.py

@@ -12,7 +12,7 @@
 
 {
     "name": "Recurring - Contracts Management",
-    "version": "19.0.1.1.3",
+    "version": "19.0.1.1.4",
     "category": "Contract Management",
     "license": "AGPL-3",
     "author": "Tecnativa, ACSONE SA/NV, Odoo Community Association (OCA)",

contract/views/contract_portal_templates.xml

@@ -93,7 +93,17 @@
                     />
                 </t>
             </t>
-            <div class="row o_portal_sale_sidebar">
+            <!--
+                NB: do NOT use the class "o_portal_sale_sidebar" here. That
+                class is the binding selector for the sale / sale_management
+                frontend interactions (SaleSidebar, SaleUpdateLineButton,
+                PortalPrepayment). SaleUpdateLineButton.setup() does
+                `this.el.querySelector("table#sales_order_table").dataset`,
+                which throws a TypeError on the contract page because there is
+                no sale-order table here. The contract portal page needs no JS
+                interaction, so use the neutral "o_portal_sidebar" class.
+            -->
+            <div class="row o_portal_sidebar">
                 <div class="d-flex col-lg-4 col-xxl-3 d-print-none">
                     <div
                         id="sidebar_content"