Translate a JSON term into an application term. This
transformation is based on :- json_object/1 declarations. An
efficient transformation is non-trivial, but we rely on the
assumption that, although the order of fields in JSON terms is
irrelevant and can therefore vary a lot, practical applications
will normally generate the JSON objects in a consistent order.
If a field in a json_object is declared of type boolean, @true
and @false are translated to true or false, the most
commonly used Prolog representation for truth-values.