src: replace SetNamedPropertyHandler()

The changes introdcued here replace the deprecated
v8 method SetNamedPropertyHandler() to SetHandler()
in node.cc.
Prior to refactoring, the method defined callbacks
when accessing object properties defined by Strings
and not Symbols.
test/parallel/test-v8-interceptStrings-not-Symbols.js
demonstrates that this behaviour remained unchanged
after refactoring.

PR-URL: https://github.com/nodejs/node/pull/9062


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>