fix: webpack resolve options

[kinetifex]

Motivation

We have some packages that export both ESM and CommonJS modules using conditional package exports using the import and require conditions, such as in this example. These work fine in our Webpack 5 apps, however if we try to use these imports in Linaria blocks with the Linaria Webpack loader, it blows up with the error:

Package path ./sizes is not exported from package

Summary

What's missing is that the Linaria webpack loaders do not pass down the appropriate conditionNames to the enhanced resolver. This PR adds the require condition name by default, and also introduces the ability to customing the loader resolveOptions.

Test plan

@rmazzeo-godaddy put together this repo that reproduces the problem.

git clone git@github.com:rmazzeo-godaddy/linaria-conditionnames-missing.git
cd linaria-conditionnames-missing
npm ci
npm run start

[callstack-bot]

Hey @kinetifex, thank you for your pull request 🤗.
The coverage report for this branch can be viewed here.