feat: add mjs support

[rishabh3112]

What kind of change does this PR introduce?
Support for .mjs configs

Did you add tests for your changes?

If relevant, did you update the documentation?

Summary
It is extension of @anshumanv's PR with support for esm configs using esm package.

Does this PR introduce a breaking change?

Other information
The standard await import() will not work as nodejs/node#32985 has been reverted.
Using esm package in this PR to have esm interop

[evenstensberg]

Tests are failing

[rishabh3112]

Tests are failing

@evenstensberg Yes, because esm package is not working properly here. I couldn't find upon investigation on how to make it work.
So, I need help.

[alexander-akait]

I think we don't need package, we can use this idea https://github.com/gulpjs/gulp-cli/blob/master/lib/shared/require-or-import.js

[webpack-bot]

@rishabh3112 Thanks for your update.

I labeled the Pull Request so reviewers will review it again.

@evenstensberg Please review the new changes.

[rishabh3112]

I think we don't need package, we can use this idea https://github.com/gulpjs/gulp-cli/blob/master/lib/shared/require-or-import.js

Same not working again locally.

[alexander-akait]

@rishabh3112 what is node you are use (version)?

[rishabh3112]

Tried on 12, 13 and 14. (I use fnm)

[alexander-akait]

Maybe something broken in fnm? I use nvm and tests for gulp-cli worked with mjs

[rishabh3112]

Maybe something broken in fnm? .

Can't say for sure. Lets see CI, if still not passed then can you try checking out this branch and testing locally once?

[anshumanv]

I tried with nvm in the past, no luck 😞

[anshumanv]

Yep would be great if @evilebottnawi can check once