fix: fixture path to support commonjs and esm

[sewnagP]

Added a support for the commonjs and ESM to fixturepath.

Description

Motivation and Context

Screenshots (if appropriate):

Checklist:

• I have updated/added documentation affected by my changes.
• I have added tests to cover my changes.

[mlrawlings]

Hey, thanks for the PR!

I'm happy to support this, however as it stands, this PR changes when require is called (it's now immediately rather than upon usage).

If you wouldn't mind addressing that, I'll merge this once the change is made.

---

A bit more context:
This desire for lazy evaluation is why fixture is a getter and the require call is inside the render function. Since this library is intended to be used by tests, this means that a fixture with an error will cause a specific test to fail rather than blow up the whole suite. In some cases, you may even want to test that a certain fixture throws. Or if you grep/it.only to run a specific test, the suite is slowed down by unnecessarily loading all the fixtures.

[sewnagP]

@mlrawlings Thanks, addressed the comments.