String filter events

The \Zikula\SecurityCenterModule\Api\HtmlFilterApiInterface class provides this event:

/**
 * Occurs when a string is passed to HtmlFilterApi and filtered.
 * An instance of Zikula\Bundle\CoreBundle\Event\GenericEvent, the data is the filterable string.
 */
public const HTML_STRING_FILTER = 'htmlfilter.outputfilter';