fix : Make OIDC logout working when end_session_endpoint is present in configuration - MEED-10192 - #4024

Before this fix, when using OIDC, some IDP provide a endsession_endpoint url, to make a logout on the IDP after being loggued out from the SP, and eXo do not use this url
This commit ensure to send the user in this url if existing and if property exo.oauth.openid.propagate.logout is set to true
To achieve this modification, this commit create a new handler in the platform to manage the logout : LogoutHandler on /portal/logout. The old logout code (UIPortal.LogoutActionListener) is removed

Resolves #4024

Author: rdenarie

packaging/plf-packaging-resources/src/main/resources/controller.xml

@@ -54,6 +54,13 @@ Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
     </route-param>
   </route>
 
+
+  <route path="/logout">
+    <route-param qname="gtn:handler">
+      <value>logout</value>
+    </route-param>
+  </route>
+
   <route path="/download">
     <route-param qname="gtn:handler">
       <value>download</value>