[FIX] project: display title instead of empty block

Steps:
- Open Website > My Account > Projects
- Open the project in which the customer is not set
- Now perform 'group by customer' on that project.

Issue:
- A blank line is shown below the header line.

Cause:
- No condition is applied to it when we do not have a customer set.

Fix:
- Adding condition to display 'No Customer' instead of an empty block.

closes odoo/odoo#136734

Task: 3461563
X-original-commit: 0649a1d12ef9ecd5ff680679eb2c6151287cc22e
Signed-off-by: Xavier Bol (xbo) <xbo@odoo.com>

addons/project/i18n/project.pot

@@ -2781,6 +2781,11 @@ msgstr ""
 msgid "Next Activity Type"
 msgstr ""
 
+#. module: project
+#: model_terms:ir.ui.view,arch_db:project.portal_tasks_list
+msgid "No Customer"
+msgstr ""
+
 #. module: project
 #: model_terms:ir.ui.view,arch_db:project.portal_tasks_list
 msgid "No Milestone"

addons/project/views/project_portal_project_task_templates.xml

@@ -54,7 +54,11 @@
                             <th t-if="groupby == 'status'" t-attf-colspan="{{grouped_tasks_colspan}}">
                                 <span class="text-truncate" t-field="tasks[0].sudo().state"/></th>
                             <th t-if="groupby == 'customer'" t-attf-colspan="{{grouped_tasks_colspan}}">
-                                <span class="text-truncate" t-field="tasks[0].sudo().partner_id.name"/></th>
+                                <span t-if="tasks[0].sudo().partner_id"
+                                      class="text-truncate"
+                                      t-field="tasks[0].sudo().partner_id.name"/>
+                                <span t-else="">No Customer</span>
+                            </th>
                         </tr>
                     </tbody>
                     <tbody t-if="tasks">