[FIX] hr_holidays: add employee in the event title of the calendar view

Issue:
In the calendar view of Time Off (Approvals / Time Off),
we see the "display_name" of the events,
but we don't see explicitly the name of the employees
associated with the events.

Solution:
Change the title of the event
by adding the employee's name at the beginning.

opw-3239972

closes odoo/odoo#116942

Signed-off-by: Kevin Baptiste <kba@odoo.com>

addons/hr_holidays/static/src/views/calendar/calendar_model.js

@@ -13,6 +13,18 @@ export class TimeOffCalendarModel extends CalendarModel {
         }
     }
 
+    /**
+     * @override
+     */
+    normalizeRecord(rawRecord) {
+        let result = super.normalizeRecord(...arguments);
+        if (rawRecord.employee_id) {
+            const employee = rawRecord.employee_id[1];
+            result.title = [employee, result.title].join(' ');
+        }
+        return result;
+    }
+
     makeContextDefaults(record) {
         const { scale } = this.meta;
         const context = super.makeContextDefaults(record);