Make ReplaceMisspelledWord web-actions more generic

Instead of using four numbered web-actions, use a generic method that
can be called using the context data.

Change-Id: If31c6f572c54d7ecfc7962edea2e27c555e6d79f
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@theqtcompany.com>