Bug 316298 [Compatibility] Support o.e.ui.menus visibleWhen
We need support in MCoreExpression for entire expressions created by the WorkbenchMenuService. They don't often use ReferenceExpressions to core expression definitions. PW
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/workbench/UIEvents.java
public static final String TOPIC = UITopicBase + "/menu/Menu"; 
		public static final String ENABLED = "enabled"; 
	}
	public static interface MenuContribution {
		public static final String TOPIC = UITopicBase + "/menu/MenuContribution"; 
		public static final String POSITIONINPARENT = "positionInParent"; 
	}
	public static interface MenuContributions {
		public static final String TOPIC = UITopicBase + "/menu/MenuContributions"; 
		public static final String MENUCONTRIBUTIONS = "menuContributions"; 
	}
	public static interface MenuItem {
		public static final String TOPIC = UITopicBase + "/menu/MenuItem"; 
		public static final String MNEMONICS = "mnemonics"; 
	}
	public static String buildTopic(String topic) {
		return topic + TOPIC_SEP + ALL_SUB_TOPICS;
	}
	public static String buildTopic(String topic, String attrName) {
		return topic + TOPIC_SEP + attrName + TOPIC_SEP + ALL_SUB_TOPICS;
	}
	public static String buildTopic(String topic, String attrName, String eventType) {
		return topic + TOPIC_SEP + attrName + TOPIC_SEP + eventType;
	}
}