Add setting "personal_agenda_show_all_session_events"

To show all session agenda events in personal agenda.
See BT#12156

main/inc/lib/agenda.lib.php

@@ -1173,11 +1173,15 @@ class Agenda
                     $this->getPlatformEvents($start, $end);
                 }
 
+                $ignoreVisibility = api_get_configuration_value('personal_agenda_show_all_session_events');
+
                 // Getting course events
                 $my_course_list = array();
                 if (!api_is_anonymous()) {
                     $session_list = SessionManager::get_sessions_by_user(
-                        api_get_user_id()
+                        api_get_user_id(),
+                        $ignoreVisibility
+
                     );
                     $my_course_list = CourseManager::get_courses_list_by_user_id(
                         api_get_user_id(),

main/install/configuration.dist.php

@@ -267,6 +267,6 @@ $_configuration['system_stable'] = NEW_VERSION_STABLE;
 //$_configuration['show_prerequisite_as_blocked'] = false;
 // Mail header extra HTML attributes
 //$_configuration['mail_header_style'] = '';
-
-
+// Show all agenda events in personal agenda from all session no matter the visibility.
+//$_configuration['personal_agenda_show_all_session_events'] = false;