test: add addon tests for `RegisterSignalHandler()`

Ensure coverage for the different combinations of arguments.

PR-URL: https://github.com/nodejs/node/pull/27775
Refs: https://github.com/nodejs/node/pull/27246


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>