Migrating to SPA

Our view functions are getting larger and less readable, and I think it's good time to migrate to a versatile JavaScript framework solely for frontend.

The problem with the current templates are:
- jQuery is hard. Virtual DOM does the job better.
- The maintenance of the libraries are falling. For instance, jQuery UI has already gone unmaintained. Also applies to some Django extensions.

These problems can be solved with single-page apps. In the Vue.js community, there are plenty of CSS framework wrapper, or modular components maintained. We also get server-side rendering, well optimized webpack bundles and Babel using [Nuxt.js](https://nuxtjs.org).

In order to migrate incrementally, we can first build a complete API with Django-rest-framework.

It would be a good idea to do a visual refresh alongside this costly refactor. Please express your opinions in comments.

The issue names no specific files, tests, or entry points; start by reviewing the current view functions, templates, and Django extensions. The proposal does not define a concrete completion criterion, so the migration scope and visual-refresh expectations need to be settled before implementation.

Written by the indexing model from the issue text.