Update to support latest craco alpha

[tomap]

(webpack 5 & react-scripts 5 compatible)

You might not want to use my package-lock.json but releasing an alpha version matching the craco alpha version would be great :)

(I'm not 100% sure that adding webpack 5 as a dependency is necessary)

[dbgordon09]

@hasanayan - The version of craco you have listed in this plugin has webpack 4 as a dependency. Therefore container is undefined on webpack and it crashes when trying to build.

@tomap's changes solve these issues by both upgrading the craco dependency and including webpack 5 as a bundled dependency. Please merge this 🙏