TASK: Use mre fine-grained sanitation

The previously used `[[:^alnum:]]` strips german umlauts and valid characters of other languages which leeds to strange query results.

This is more fine grained approach to sanitize the search word based on elasticsearch recommendations.

Author: daniellienert

Classes/Controller/SuggestController.php

@@ -114,8 +114,8 @@ protected function buildRequestForTerm(string $term, string $contextNodeIdentifi
         $term = strtolower($term);
 
         // The suggest function only works well with one word
-        // and the term is trimmed to alnum characters to avoid errors
-        $suggestTerm = preg_replace('/[[:^alnum:]]/', '', explode(' ', $term)[0]);
+        // special search characters are escaped
+        $suggestTerm = str_replace(['=', '>', '<', '(', ')', '{', '}', '[', ']', '^', '"', '~', '*', '?', ':', '\\', '/'], ['', '', '', '(', '\)', '\{', '\}', '[', '\]', '\^', '\"', '\~', '\*', '\?', '\:', '\\\\', '\/'], explode(' ', $term)[0]);
 
         if (!$this->elasticSearchQueryTemplateCache->has($cacheKey)) {
             $contentContext = $this->createContentContext('live', $dimensionCombination ? json_decode($dimensionCombination, true) : []);