Add JCasC support for publish-over-ssh hosts

The compatibility of publish-overs-ssh plugin is incomplete. I can apply BapSshCommonConfiguration via JCasC. But I cannot configure hosts, i.e. apply BapSshHostConfiguration via JCasC. As XML that configuration is placed in $JENKINS_HOME/jenkins.plugins.publish_over_ssh.BapSshPublisherPlugin.xml