Bundle Menas resources

## Background
Currently, Menas has a lot of `js` files which are fetched separately on load. This abundance of HTTP requests slows down loading the application. This will only grow over time.

## Feature
We should bundle our resources and serve them all at once.

## Proposed Solution [Optional]
We can use something like
1. https://webpack.js.org
2. https://parceljs.org (less configuration than webpack, an interesting choice)
3. https://github.com/eirslett/frontend-maven-plugin (maven plugin to run npm commands as part of the build)