test: consolidate n-api test addons - part2

It takes time to build each of the addons used to test n-api.
Consolidate a few of the smaller ones to save build time.

Get rid of one more small addon.

PR-URL: https://github.com/nodejs/node/pull/13380


Reviewed-By: Jason Ginchereau <jasongin@microsoft.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>