Do not reference SchemaNode.getPath() in BindingRuntimeTypes

We have a call site which is referencing SchemaNode.getPath() in order to reconstruct SchemaNodeIdentifier for a SchemaNode.

This facility is only used for actions, but may actually also be used for notifications. Devise a replacement addressing construct allow this identification.

Given that the number of actions and notifications can be potentially large, we'll probably need an addressing construct which relies on recursion, similar to YangInstanceIdentifier and SchemaPath.