Reduce GraphVisitor interface.
In relation to "Graph-oriented Rules Concept Proposal",
https://docs.google.com/document/d/1UOihPv_zryFilCb7T0k8992wPUt3YNP4goh9rxTC7ng/edit#

This change would also make these unused:

import org.jboss.windup.graph.model.meta.javaclass.EjbEntityFacet;
import org.jboss.windup.graph.model.meta.javaclass.EjbSessionBeanFacet;
import org.jboss.windup.graph.model.meta.javaclass.MessageDrivenBeanFacet;
import org.jboss.windup.graph.model.meta.javaclass.SpringBeanFacet;
import org.jboss.windup.graph.model.meta.xml.EjbConfigurationFacet;
import org.jboss.windup.graph.model.meta.xml.NamespaceMeta;
import org.jboss.windup.graph.model.meta.xml.SpringConfigurationFacet;