Juwang-bind set entry update and test cases

This PR is to fix a bug in ConfigurationBuilderImpl when adding List support. 

In ConfigurationBuilderImpl, namespace (class hierarchy) could be an instance of  ClassHierarchyImpl, could be ProtocolBufferClassHierarchy. Simply casting it to ClassHierarchyImpl would cause an exception.  In bindSetEntry(NamedParameterNode<Set<T>> iface, String impl), an instance checking is added to avoid such an issue. 

Test cases are also added to cover the code path.