[mod] option to enable or disable "proxy" button next to each result (#54)

* [mod] option to enable or disable "proxy" button next to each result

Closes: https://github.com/searxng/searxng/issues/51


Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
Co-authored-by: Alexandre Flament <alex@al-f.net>