Use nginx to serve static files for Nuxt

[sarayourfriend]

Problem

The Nuxt server currently handles serving static file requests. These files would be much better served by Nginx, similar to how we serve static files for Django.

Description

After #3118 is addressed to remove the complex build contexts (started here #3141) it will be much easier to move the Nginx container build into the same Dockerfile as the general frontend, at which point we will be able to copy the Nuxt build files from the frontend image into the Nginx image and configure it to serve those requests on the /_nuxt location.

Additional context

I've already added documentation for this in the frontend nginx container build: #3108 (comment)

We'll need to build on that after the related issues are resolved to simplify the frontend build and remove the complex build contexts.