n-api: correct instance data tests

When instance data was backported, some of the tests ended up in a
location where they do not get run. This moves the tests into
test/addons-napi, merging them with existing tests therein, thereby
ensuring that they do get run.

PR-URL: https://github.com/nodejs/node/pull/32488


Reviewed-By: Beth Griggs <Bethany.Griggs@uk.ibm.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>