Schematics: Refactor NodeResolver and add NodeResolveMethod

Schematics: Refactor NodeResolver and add NodeResolveMethod

NodeResolver name lists now belong to the NodeResolver object instead of
the associated NodeDefManager.  In addition to minimizing unnecessary
abstraction and overhead, this move permits NodeResolvers to look up nodes
that they had previously set pending for resolution.  So far, this
functionality has been used in the case of schematics for
serialization/deserialization.