fix(optimizer): external require-import conversion (fixes #2492, #3409, #5308)

[sapphi-red]

Description

This PR uses esbuild's plugin hook to convert require into import even if it is externalized. (refs: #2492 (comment))

a minimal require-import conversion plugin: https://stackblitz.com/edit/node-xh6pvc?file=build.js

fixes #2492
fixes #3409
fixes #5308

I tested with #3409's repro.

Additional context

I think this approach is faster and less-fragile than regex or parsing + replacing. But it heavily depends on esbuild's plugin behavior and it might unveil an edge case bug of esbuild.

---

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

[bluwy]

Neat trick. One nitpick below but this seems like a great solution. I don't think there are cases where we would actually want to preserve the require.

[patak-dev]

Nice, I agree this looks like a good move forward. Lets try it in the next alpha so we check how it works in the wild.

Tests are failing for node 16, I'll merge it anyways like the prev PRs. I hope node fix the seg fault soon or we find