🐛(frontend) fix image flash when navigating previews

Add a key prop to force React to remount the img element
when switching files. Without this, transitioning between
images of very different sizes causes a visual splash.

src/frontend/apps/drive/src/features/ui/preview/FilesPreview.tsx

@@ -152,6 +152,8 @@ export const FilePreview = ({
             src={currentFile.url_preview}
             alt={currentFile.title}
             className="file-preview__viewer"
+            // This is made to avoid splash effect when switching between images having a huge size difference.
+            key={currentFile.id} 
           />
         );
       case MimeCategory.VIDEO: