fix(MultimediaViewer): 🐛 fix clipped image when info card is collapsed

In addition to removing the background when the info card is collapsed,
the backdrop filter should also be removed.

Author: alistair3149

skinStyles/extensions/MultimediaViewer/mmv.less

@@ -213,6 +213,8 @@
 	color: ~'hsl( var( --color-progressive-hsl__h ), 45%, 80% )'; // color-base in dark mode
 	background-color: transparent;
 	border-color: transparent;
+	-webkit-backdrop-filter: none;
+	backdrop-filter: none;
 
 	.mw-mmv {
 		&-title-para {