esm: refactor esm tests out of test/message

[GeoffreyBooth]

Resolves #40920 (comment).

This PR refactors the ESM tests that are currently in test/message to instead be with the rest of the ESM tests in test/es-module. This meant rewriting them from the .out style to instead spawn child processes. This has two benefits:

1. Running tools/test.py -J es-module now does, in fact, run all the ESM tests.
2. Refactors to the ESM loader and associated files that change the call stack no longer require updating a bunch of .out files’ stack traces.

In addition, there were some duplicated import assertion tests that I removed; and I slimmed down a few fixtures that we could do without.

cc @nodejs/modules @nodejs/loaders