Allow listing all module nodes with moduleName:*

Change-Id: I1c9d8ace936641db06f38c292655b3c5c5557385
diff --git a/src/schema.hpp b/src/schema.hpp
index e0d30af..b5e17a2 100644
--- a/src/schema.hpp
+++ b/src/schema.hpp
@@ -79,4 +79,5 @@
     virtual const std::set<std::string> validIdentities(const schemaPath_& location, const ModuleNodePair& node, const Prefixes prefixes) const = 0;
     virtual const std::set<std::string> enumValues(const schemaPath_& location, const ModuleNodePair& node) const = 0;
     virtual std::set<std::string> childNodes(const schemaPath_& path, const Recursion recursion) const = 0;
+    virtual std::set<std::string> moduleNodes(const module_& module, const Recursion recursion) const = 0;
 };