Remove Nuxeo Startup Wizard

Remove the Nuxeo Startup Wizard from the nuxeo-server-tomcat as it does not make any sense while delivering a Nuxeo Server Docker image: the wizard changes the configuration at runtime and restarts the Nuxeo Server inside the running docker container.

Remove the nuxeo-startup-wizard and nuxeo-wizard-tests Maven modules.

Take care of the packages.xml file and setupWizardDownloads folder.

Update https://qa.nuxeo.org to disable/remove the related jobs.

Update documentation if needed.