proxy /static/rest_framework/ to the django API

[EamonTracey]

Issue: AAH-2148

This properly loads the CSS for DRF's API views in the browser.

[himdel]

LGTM 👍

• insights* tests are currently broken, feel free to ignore those,
• misc failure is unrelated, fixed in Remove alert from Task list view #4009
• webpack-config is expected and ok, this is intentionally changing that config :)

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That said, is there a corresponding oci-env PR?
Because /static/rest_framework/ only seems to be available when using the docker-compose dev env, not in oci-env.