Use the request path base when creating location header urls

[Louis9902]

Use the request path base when creating url for the upload location header. The base base is only used for the endpoint based invoker, as this is backwards compatible with the previouse behaviour.

The middleware approach always defined the absolut url which is used, and if there are existing configurations which include the path base this will break the backwards compat.

[smatsson]

Thanks for this PR! This seems like a bug on my end. I'll run some tests and merge if everything looks ok 👍

Are you running tusdotnet as a virtual application in IIS or are you routing it through a subfolder in a reverse proxy?

[Louis9902]

It depends, we deploy via IIS or as Standalone with Krestrel and a reverse proxy. When running in IIS it's ran as virtual application.

[smatsson]

Fixed some issues in the PR (see commits above). Still needs some more testing. Test setup used was a nginx reverse proxy running the following config:

  location /tusdotnet {
            proxy_buffering off;
            proxy_pass http://localhost:5008;
        }

The net6 test app was updated to use this path base:

app.UsePathBase("/tusdotnet/");