Webview authentication for custom auth or captcha

[filcuk]

Describe your suggested feature

I would like to suggest an option to get authentication session using webview.
The scenario where this would be necessary is where the qBittorrent web UI is behind a separate layer of authentication (e.g. Authelia) or similar.

Using webview, user can authenticate as usual, which would allow the app to keep a session for its duration.

I'm splitting this from #110, as I appear to have misunderstood the original ticket.

Additional details

No response