test: move ESM fixtures to fixtures dir

Also consistently import the `common` module where possible.

PR-URL: https://github.com/nodejs/node/pull/19409


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Guy Bedford <guybedford@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Khaidi Chu <i@2333.moe>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>