upgrade babel-loader to v9 and migrate to webpack 5 asset modules

- Upgrade babel-loader from v8.1.0 to v9.1.0 to resolve loader-utils v3 compatibility
- Remove file-loader dependency and migrate to webpack 5 built-in asset modules
- Fix build errors: "loaderUtils.getOptions is not a function"
- Both Chrome and Firefox builds now compile successfully

Author: leonardoventurini