approvals: improve page title

To easily identify which page is which (between /job-seekers/details/ &
/approvals/detail/)

itou/templates/approvals/detail.html

@@ -7,7 +7,7 @@
     {% include "layout/previous_step.html" with back_url=back_url only %}
 {% endblock %}
 
-{% block title_content %}<h1>{{ approval.user.get_full_name }}</h1>{% endblock %}
+{% block title_content %}<h1>Salarié : {{ approval.user.get_full_name }}</h1>{% endblock %}
 
 {% block content %}
     <section class="s-section">