refactor(app): backport technical changes (#4679)

* refactor(app): backport technical changes

* refactor(app): remove EE only features

* feat(app): small review changes to match EE codebase layout on some files

Co-authored-by: xAt0mZ <baron_l@epitech.eu>

webpack/webpack.common.js

@@ -60,6 +60,15 @@ module.exports = {
       },
     ],
   },
+  devServer: {
+    contentBase: path.join(__dirname, '.tmp'),
+    compress: true,
+    port: 8999,
+    proxy: {
+      '/api': 'http://localhost:9000',
+    },
+    open: true,
+  },
   plugins: [
     new HtmlWebpackPlugin({
       template: './app/index.html',