I was testing the new Kagi engine and found for some queries I was getting a
`KeyError` exception from the result parsing.
This PR ensures we only assumes the `url` key exists, and we use `.get()` to
retrieve values for keys that may not be present.
Their API documentation [1] clarifies that only the `url` and `title` properties
are required/guaranteed in the search result object, but this is not correct:
File "/home/patrick/code/searxng/searx/engines/kagi.py", line 161, in response
title=html.unescape(result["title"]),
~~~~~~^^^^^^^^^
KeyError: 'title
Heard back from Kagi support:
> The image results "title' should be marked as optional, as many images likely
> don't have titles - as you've noticed. The only required field there should be
> the "url" field.
[1] https://kagi.redocly.app/api/docs/openapi/search/search#search/search/t=response&c=200&path=data/search
[2] https://github.com/searxng/searxng/issues/2247#issuecomment-4692976877
