Pure react with dynamic imports in the browser
Main reason to use ES Module Shims here is to get Import Maps support.
UMD is not compatible with ES modules: https://github.com/umdjs/umd/issues/124
https://github.com/guybedford/es-module-shims/issues/18 https://stackoverflow.com/questions/49054293/serviceworker-fails-on-hard-reload-ctrl-shift-r-in-chrome