Add missing avatar class so that CSS applies to ActivityPub Avatars on the Dashboard (#1932)

Author: pfefferle

.github/changelog/1932-from-description

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fixed
+
+Fixed missing avatar class so that CSS styles are correctly applied to ActivityPub avatars on the Dashboard.

includes/class-activitypub.php

@@ -356,7 +356,10 @@ public static function pre_get_avatar_data( $args, $id_or_email ) {
 
 			/** This filter is documented in wp-includes/link-template.php */
 			$args['url']     = \apply_filters( 'get_avatar_url', $avatar, $id_or_email, $args );
+			$args['class'][] = 'avatar';
 			$args['class'][] = 'avatar-activitypub';
+			$args['class'][] = 'avatar-' . (int) $args['size'];
+			$args['class'][] = 'photo';
 			$args['class'][] = 'u-photo';
 			$args['class']   = \array_unique( $args['class'] );
 		}