feat: Support ESM test running via the test task

[phated]

• I talked about the limitations in the ESM PR and suggestion in the ts-node transpile PR and discussed this with @fvictorio

---

This builds upon #3155 to support loading ESM tests within a "type": "module" when using hardhat in commonjs mode. It requires the .cjs support from #3155 and then a one-line change to make mocha attempt to load ESM modules.

I can rebase this when the other PR lands to just the last commit (check that out for the smaller diff).

I'm getting some parallel test failures, but those seem to exist for the CJS runs currently (maybe related to #3153?)

[changeset-bot]

⚠️ No Changeset found

Latest commit: 19b9a86

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Updated
hardhat	✅ Ready (Inspect)	Visit Preview	Sep 23, 2022 at 10:15AM (UTC)
hardhat-storybook	✅ Ready (Inspect)	Visit Preview	Sep 23, 2022 at 10:15AM (UTC)

[github-actions]

This issue is also being tracked on Linear.

We use Linear to manage our development process, but we keep the conversations on Github.

LINEAR-ID: f7739f98-fb6e-400e-ad17-25ffd7215590

[github-actions]

Thanks for submitting this PR!

Unfortunately, it has some linter errors, so we can't merge it yet. Can you please fix them?

Running yarn lint:fix in the root of the repository may fix them automatically.

[fvictorio]

I'm not sure why these tests are failing, but I'll look into it.