Add existing server files to a project in the web UI

When I create a project in the web UI I can either provide a URL or upload a file from my local desktop to the server as a scanpipe project input.

In addition to these, there is a use case where I have moved manually a large archive to the scancode.io server before hand because this is not accessible via a URL or too big to upload from a web-browser.

In this case, I would to have a file picker in the web UI to list and select these files and use these as project inputs. This should be limited to a well-defined directory.