[FIX] hr_org_chart: undefined manager name in breadcrumbs

Before this commit, in the organization chart, when a manager that have too many
subordinates, and we want to view all the subordinates clicking the '...' button. There was
an error in the breadcrumbs, the text 'Undefined' was shown in the place of the manager's
name.

Now, the breadcrumbs shows the name of the manager.

OPW-1923990

closes odoo/odoo#30231

addons/hr_org_chart/static/src/xml/hr_org_chart.xml

@@ -105,6 +105,7 @@
                 <div class="media-left">
                     <a href="#"
                         t-att-data-employee-id="self.id"
+                        t-att-data-employee-name="self.name"
                         class="well o_org_chart_show_more media-object text-center o_employee_sub_redirect">&#8230;</a>
                 </div>
             </div>