src: pass context to Get() operations for cares_wrap

Using Get() without the context argument will soon be deprecated.
This also passed context to Int32Value() operations as well.

PR-URL: https://github.com/nodejs/node/pull/16641


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: James M Snell <jasnell@gmail.com>