Allow style HTML attribute in video tag in body (#4426)

This enables templates and experiments with embedded videos of custom
size.

src/services/Filter.php

@@ -166,7 +166,7 @@ public static function body(?string $input = null): string
         // create base config for html5
         $config = HTMLPurifier_HTML5Config::createDefault();
         // allow only certain elements
-        $config->set('HTML.Allowed', 'div[class|style],br,p[class|style],sub,img[src|class|style|width|height],sup,strong,b,em,u,a[href],s,span[style],ul,li,ol[style],dl,dt,dd,blockquote,h1[class|style],h2[class|style],h3[class|style],h4[class|style],h5[class|style],h6[class|style],hr,table[style|data-table-sort|border],tr[style],td[style|colspan|rowspan],th[style|colspan|rowspan],code,video[src|controls],audio[src|controls],pre[class],details,summary,figure,figcaption');
+        $config->set('HTML.Allowed', 'div[class|style],br,p[class|style],sub,img[src|class|style|width|height],sup,strong,b,em,u,a[href],s,span[style],ul,li,ol[style],dl,dt,dd,blockquote,h1[class|style],h2[class|style],h3[class|style],h4[class|style],h5[class|style],h6[class|style],hr,table[style|data-table-sort|border],tr[style],td[style|colspan|rowspan],th[style|colspan|rowspan],code,video[src|controls|style],audio[src|controls],pre[class],details,summary,figure,figcaption');
         $config->set('HTML.TargetBlank', true);
         // configure the cache for htmlpurifier
         $tmpDir = FsTools::getCacheFolder('purifier');