Support Webpack 5

🐛 Bug Report

When I build with webpack 5.0.0-rc.0, I have an error TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string. Received an instance of Object, because in loadable-stats.json field assets generated as

 "assets": [{ "name": "assetname.js" }]

but chunkExtractor expects

"assets": ["assetname.js"]

To Reproduce

Steps to reproduce the behavior:

1. Use webpack 5.0.0-rc.0
2. loadable-stats:

 "assets": [
        {
          "name": "assetname.js"
        }
  ]

Expected behavior

Support new schema of assets

## System:
 - OS: macOS 10.15.6
 - CPU: (16) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
 - Memory: 1.45 GB / 16.00 GB
 - Shell: 5.7.1 - /bin/zsh
## Binaries:
 - Node: 14.9.0 - ~/.nvm/versions/node/v14.9.0/bin/node
 - Yarn: 1.22.4 - /usr/local/bin/yarn
 - npm: 6.14.8 - ~/.nvm/versions/node/v14.9.0/bin/npm
## npmPackages:
 - @loadable/babel-plugin: 5.13.2 => 5.13.2 
 - @loadable/component: 5.13.2 => 5.13.2 
 - @loadable/server: 5.13.2 => 5.13.2 
 - @loadable/webpack-plugin: 5.13.0 => 5.13.0 

[xnerhu]

Any progress?

[theKashey]

The new version with webpack5 support has not yet been released. I am working on a proper test to ensure everything is working properly.