Auto-suggest dropdown doesn't appear after connecting to SearchStax

For the proposed solution, we should make it generic so it reads from whatever is the attribute name in `foreach ($data['suggest'][attributeName][$user_input]['suggestions'] ?? [] as $suggestion) {`

based on the language, the attributeName as be different

drunken monkey → made their first commit to this issue’s fork.

There actually is already code that should be handling this nested structure:

      while (count($data) === 1) {
        $tmp = reset($data);
        if (!is_array($tmp)) {
          break;
        }
        $data = $tmp;
      }

However, it seems since I wrote this the response structure has slightly changed: an additional metadata property has been added at the top level so the count($data) === 1 check fails right away. The changes in this MR should fix the functionality again while still keeping the code as flexible as possible wrt different keys used in the response.
Please review!

Merged.