Enhancement/Integrate Webpack and Django

[c-w]

This is a follow-up to #80.

This pull request more tightly integrates Django asset serving with the Webpack compiler. Specifically, after this change, it will no longer be required to manually compile the project's Javascript to integrate it with the Django server. Instead the Javascript will be compiled and reloaded on the fly automatically.

In a development scenario (here emulated by running the server as described in the README), the assets get linked via the hot reloading Webpack development server:

This enables a number of enhancements to the developer experience, including not having to manually run the Webpack build and also being able to debug Javascript before it went through the build process:

In a production scenario (here emulated by running the server via Docker), the assets get directly linked from the compiled static bundles folder as before:

[Hironsan]

Thanks!