[Feature]: Support reverse proxies using PAPERLESS_HTTP_REMOTE_USER_HEADER_NAME and PAPERLESS_ENABLE_HTTP_REMOTE_USER together with basic auth

[danieldietsch]

Description

Paperless allows you to use basic auth together with PAPERLESS_HTTP_REMOTE_USER_HEADER_NAME to trust usernames provided in your http header.
I am using this feature with apache as reverse proxy, where I essentially do

RequestHeader unset Authorization
RequestHeader set HAHAHA %{REMOTE_USER}s

and as paperless env var

PAPERLESS_ENABLE_HTTP_REMOTE_USER=true
PAPERLESS_HTTP_REMOTE_USER_HEADER_NAME="HTTP_HAHAHA"

This allows me to pass usernames via http to paperless, and paperless just accepts them as authenticated. I was using https://github.com/bauerj/paperless_app before, but since my last paperless-ngx update, this app does not work anymore (and it seems like development there is dead).

Unfortunately, I cannot use paperless-mobile, as it does not support this paperless feature.

It would be very nice if you would support BasicAuth in this way.