[TASK] Allow and replace special characters like umlauts

Currently ``<v:format.uri.sanitizeString />`` strips all special characters like umlauts which is not what one would expect. Open for discussion though is if this feature should be configurable via viewhelper argument.
I think it would be neater to make the source/replace arrays into one array with $source=>$replace, then extract using `array_keys` and `array_values` before `str_replace`. That would keep the dimensions of both arrays always in sync.