Pick pass cookies from searxng (#3252)

* [enh] Allow passing headers/cookies from settings.yml

Example:

   - engine: xpath
   - search_url: example.org
   - headers: {'example_header': 'example_header'}
   - cookies: {'safesearch': 'off'}

* [fix[ Update only cookies/headers

* [enh] XPath engine - add time range support

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

* [enh] XPath engine - add time safe-search support

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

Co-authored-by: Allen <64094914+allendema@users.noreply.github.com>
Co-authored-by: Markus Heiser <markus.heiser@darmarit.de>