Make the Management API exposed on another port than the default one

By default, Nuxeo is accessible through the port 8080, the Management API should be exposed through another port such as 9090.

From Antoine Taillefer in NXP-27370:

About the port, after discussing with Damien and Thomas:

• The reason why we suggested to use an Nginx configuration is that we thought that it would not be possible to simply isolate the Management API by only configuring Tomcat. Yet, Damien suggested to work on a POC to have a separate webapp for the Management API in the same Tomcat - so on another port than 8080 -, hoping that it will have access to the Nuxeo Framework through the JVM, thus reach the underlying services.

• If this doesn't work, because the Management API needs the same runtime/classloader/whatever than the nuxeo webapp, then another solution can be implemented: use a Tomcat valve to set a flag (request attribute, ThreadLocal?) if the request port is the one dedicated for the Management API, then only allow access if this flag is set, otherwise return 404.