www/py-dj41-drf-spectacular-sidecar: New port

Note: Copied from www/py-drf-spectacular-sidecar, required

for NetBox 3.5.

Serve self-contained distribution builds of Swagger UI and Redoc with
Django either via runserver or collectstatic.

This Django app is an optional addition to drf-spectacular, but does not
depend on it. It may also be used independently.