Modernize JavaScript build process and dependencies for Wiki Education Dashboard

Wiki Education Dashboard (the Rails app that powers Programs & Events Dashboard) is a complex web app for keeping track of contributions to Wikimedia projects. It's widely used by the global Wikimedia community for edit-a-thons, classroom wiki writing assignments, and a variety of other initiatives. This project aims to look for areas of improvement in the javascript side of the dashboard. A major part of this would be replacing older dependencies that are no longer maintained with newer ones, reducing the bundle size, while also making the codebase in line with the rest of the JS ecosystem. This project will also involve rewriting some of the legacy code in a more modern way, making it more approachable to a wider audience of developers and contributors.