PrestaShop vulnerable to possible XSS injection through Validate::isCleanHTML method

PrestaShop is an Open Source e-commerce web application. Prior to versions 8.0.4 and 1.7.8.9, the `ValidateCore::isCleanHTML()` method of Prestashop misses hijackable events which can lead to cross-site scripting (XSS) injection, allowed by the presence of pre-setup `@keyframes` methods. This XSS, which hijacks HTML attributes, can be triggered without any interaction by the visitor/administrator, which makes it as dangerous as a trivial XSS attack. Contrary to other attacks which target HTML attributes and are triggered without user interaction (such as onload / onerror which suffer from a very limited scope), this one can hijack every HTML element, which increases the danger due to a complete HTML elements scope. Versions 8.0.4 and 1.7.8.9 contain a fix for this issue.