Upgrade to Webpack 5

[FlorentinTh]

✅ Required dependencies that are compatible :

• babel-loader
• compression-webpack-plugin
• css-loader
• handlebars-loader
• html-loader
• html-webpack-plugin
• mini-css-extract-plugin
• postcss-loader
• sass-loader
• style-loader
• terser-webpack-plugin
• webpack
• webpack-cli
• webpack-manifest-plugin

⚠️Required dependencies that are not yet compatible :

• friendly-errors-webpack-plugin see issue#123 and PR#126. Maybe use this fork.

❓ Dependencies with unknown compatibility and future requirement :

• import-glob
• webpack-merge
• clean-webpack-plugin
• progress-bar-webpack-plugin

🗑️ Dependencies no longer required :

• url-loader see webpack@5 asset modules
• file-loader see webpack@5 asset modules
• eslint-loader see webpack@5 migrate from eslint-loader
• optimize-css-assets-webpack-plugin see css-minimizer-webpack-plugin package

🚀 Setup

Apply changes explained in UPGRADE.md

[FlorentinTh]

Fixed in #fa2b4f8.