Add Django request ID to nginx log output

[sarayourfriend]

Problem

Django attaches a request ID header to responses (X-Request-Id) but this doesn't show up in Nginx logs. That means we don't have any way to easily tie Django events to specific Nginx requests.

Description

Add X-Request-Id to the Nginx JSON logging configuration.

Additional context

Testing this might be a pain as we don't have anything set up for running the Nginx configuration locally. The testing instructions from this PR will be a good starting point for getting it wired up. Essentially the Nginx image needs to be run manually via docker run with environment variables set such that the requests are forwarded to you local Django container.