feat: update Babel and Webpack configurations for design-system-website

- Replace `@babel/plugin-proposal-class-properties` with `@babel/plugin-transform-object-rest-spread`
- Update Babel and Webpack dependencies to latest versions
- Add `process` to handle polyfills
- Replace `babel-plugin-module-alias` with `babel-plugin-module-resolver`
- Update Webpack plugins configuration in `styleguide.config.js`

Author: CoMfUcIoS

packages/design-system-website/.babelrc

@@ -1,4 +1,9 @@
 {
-  "presets": ["@babel/preset-env", "@babel/preset-react"],
-  "plugins": ["@babel/plugin-proposal-class-properties"]
+  "presets": [
+    "@babel/preset-env",
+    "@babel/preset-react"
+  ],
+  "plugins": [
+    "@babel/plugin-transform-object-rest-spread"
+  ]
 }