Configuring Webpack loaders for CSSModules + Preprocessor

[sthzg]

Moved from react-webpack-generators/generator-react-webpack#248

After installing the 4.x generator with CSSModules + Preprocessor (e.g. LESS) and creating a new component the component template creates

- Foobar.js
- foobar.cssmodule.less

import styles from './foobar.cssmodule.less';
// ...
<div className="foobar-component" styleName="foobar-component" />

Rendering will fail with an exception of css module is undefined, because the loaders in cfg/base are configured for for the *.less files only and miss a test against *.cssmodule.less and a loader that is adapted for cssmodules ('css?modules&importLoaders=1&localIdentName=[name]-[local]-[hash:base64:5]').

[weblogixx]

Just added your pr, thank you!