n-api: break dep between v8 and napi attributes

The v8 n-api implementation had been depending on a one-to-one
relationship between v8 and n-api v8 property attributes.
Remove this dependency and fix coverity scan issue
165845.

PR-URL: https://github.com/nodejs/node/pull/12191


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>