Add support for https://seek.ninja (general)
It's very slow because the engine uses Server-side events, that incrementally
send data in their HTTP response [1].
I.e. we wait for the end of the response (7+ seconds), even though the results
data arrives within a few seconds -> it's very slow, because SearXNG wants to
get the full response body before it calls the `response(resp)` method
We could use httpx-sse [2], but I'm not sure how to integrate this into SearXNG
and if it's worth it
[1] https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events/
[2] https://github.com/florimondmanca/httpx-sse
Bnyro