refactor: Avatar widget

lib/pages/chat/events/message.dart

@@ -121,8 +121,8 @@ class Message extends StatelessWidget {
                   : null,
             )
           : Avatar(
-              event.sender.avatarUrl,
-              event.sender.calcDisplayname(),
+              mxContent: event.sender.avatarUrl,
+              name: event.sender.calcDisplayname(),
               onTap: () => onAvatarTab(event),
             ),
       Expanded(

lib/pages/chat/events/message_reactions.dart

@@ -213,8 +213,8 @@ class _AdaptableReactorsDialog extends StatelessWidget {
           for (var reactor in reactionEntry.reactors)
             Chip(
               avatar: Avatar(
-                reactor.avatarUrl,
-                reactor.displayName,
+                mxContent: reactor.avatarUrl,
+                name: reactor.displayName,
                 client: client,
               ),
               label: Text(reactor.displayName),