[enh] add engine AZLyrics.com (XPath)

Upstream example query:
  https://search.azlyrics.com/search.php?q=The+verbal+acupunture&w=lyrics&p=1

Cherry picked from [1] and slightly modified to pass yamllint test.

[1] https://github.com/allendema/searx/commit/8b6d5a0e5



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