wb: replace outdated jboss-sasl with wildfly-elytron

Workbench (through UF) currently depends on jboss-sasl wildfly/eap module. This module has been removed in WildFly 11/EAP7 so the WB won't deploy. We need to replace the jboss-sasl usage with wildfly-elytron which is almost drop-in replacement, just package names seem to be different. We should also directly bundle the wildfly-elytron inside the WEB-INF/lib to avoid the same issue in future.