Fix display names

lib/util/extensions/api.dart

@@ -26,18 +26,18 @@ extension GetOriginInstanceCommentView on Comment {
 
 String _extract(String url) => urlHost(url);
 
-extension DisplayName on UserSafe {
+extension DisplayNames on UserSafe {
   String get displayName {
-    final name = () {
-      if (preferredUsername != null && preferredUsername != '') {
-        return preferredUsername;
-      } else {
-        return '@${this.name}';
-      }
-    }();
+    if (preferredUsername != null && preferredUsername != '') {
+      return preferredUsername;
+    }
 
-    if (!local) return '$name@$originInstanceHost';
+    return '@$name';
+  }
 
-    return name;
+  String get originDisplayName {
+    if (!local) return '$displayName@$originInstanceHost';
+
+    return displayName;
   }
 }

lib/widgets/comment.dart

@@ -215,9 +215,6 @@ class CommentWidget extends HookWidget {
       delayedVoting.cancel();
     }
 
-    // decide which username to use
-    final username = comment.creator.displayName;
-
     final body = () {
       if (isDeleted.value) {
         return const Flexible(
@@ -363,7 +360,7 @@ class CommentWidget extends HookWidget {
                   InkWell(
                     onTap: () => goToUser.byId(
                         context, comment.instanceHost, comment.creator.id),
-                    child: Text(username,
+                    child: Text(comment.creator.originDisplayName,
                         style: TextStyle(
                           color: Theme.of(context).accentColor,
                         )),

lib/widgets/post.dart

@@ -206,7 +206,7 @@ class PostWidget extends HookWidget {
                                     style:
                                         TextStyle(fontWeight: FontWeight.w300)),
                                 TextSpan(
-                                  text: ' ${post.creator.displayName}',
+                                  text: ' ${post.creator.originDisplayName}',
                                   style: const TextStyle(
                                       fontWeight: FontWeight.w600),
                                   recognizer: TapGestureRecognizer()

lib/widgets/user_profile.dart

@@ -205,7 +205,7 @@ class _UserOverview extends HookWidget {
                   padding: EdgeInsets.only(
                       top: userView.user.avatar == null ? 10 : 0),
                   child: Text(
-                    userView.user.preferredUsername ?? userView.user.name,
+                    userView.user.displayName,
                     style: theme.textTheme.headline6,
                   ),
                 ),