[mod] presearch: add language & region support

In Presearch there are languages for the UI and regions for narrowing down the
search.  With this change the SearXNG engine supports a search by region.  The
details can be found in the documentation of the source code.

To test, you can search terms like::

   !presearch bmw :zh-TW
   !presearch bmw :en-CA

1. You should get results corresponding to the region (Taiwan, Canada)
2. and in the language (Chinese, Englisch).
3. The context in info box content is in the same language.

Exceptions:

1. Region or language is not supported by Presearch or
2. SearXNG user did not selected a region tag, example::

    !presearch bmw :en

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

0 files changed, 0 insertions, 0 deletions