Simplify Webpack Configuration

[DorianKwan]

The birth of the block explorer started with create-react-app. This was great for standing up an application quickly -- but at the cost of having less control over the configuration. To combat we have ejected react-scripts.

The benefit is now we have control but the ejected config code is highly complex as it is meant to offer a variety of application setups. Making hard to maintain, understand and extend.

This task is to simplify our Webpack setup and potentially investigate another bundler