fix: support RTL usernames in comment header

The `@` gets added by the youtube API and thus is a fixed member of
the username, so we do some simple detection logic to handle that
case (otherwise the `@` will be at the right side of a RTL username,
which is different of how Youtube displays these usernames in the
browser).

Fixes #12141

Author: VougJo23

app/src/main/java/org/schabi/newpipe/info_list/holder/CommentInfoItemHolder.java

@@ -101,14 +101,16 @@ public void updateFromItem(final InfoItem infoItem,
         }
         itemThumbnailView.setOnClickListener(view -> openCommentAuthor(item));
 
-
         // setup the top row, with pinned icon, author name and comment date
         itemPinnedView.setVisibility(item.isPinned() ? View.VISIBLE : View.GONE);
-        itemTitleView.setText(Localization.concatenateStrings(item.getUploaderName(),
-                Localization.relativeTimeOrTextual(itemBuilder.getContext(), item.getUploadDate(),
+        final String uploaderName = Localization.localizeUserName(item.getUploaderName());
+        itemTitleView.setText(Localization.concatenateStrings(
+                uploaderName,
+                Localization.relativeTimeOrTextual(
+                        itemBuilder.getContext(),
+                        item.getUploadDate(),
                         item.getTextualUploadDate())));
 
-
         // setup bottom row, with likes, heart and replies button
         itemLikesCountView.setText(
                 Localization.likeCount(itemBuilder.getContext(), item.getLikeCount()));

app/src/main/java/org/schabi/newpipe/util/Localization.java

@@ -11,6 +11,7 @@
 import android.os.Build;
 import android.text.TextUtils;
 import android.text.format.DateUtils;
+import android.text.BidiFormatter;
 import android.util.DisplayMetrics;
 import android.util.Log;
 
@@ -85,6 +86,25 @@ public static String concatenateStrings(final String delimiter, final List<Strin
                 .collect(Collectors.joining(delimiter));
     }
 
+    /**
+     * Localize a user name like <code>@foobar</code>.
+     *
+     * Will correctly handle right-to-left usernames by using a {@link BidiFormatter}.
+     *
+     * @param plainName username, with an optional leading <code>@</code>
+     * @return a usernames that can include RTL-characters
+     */
+    @NonNull
+    public static String localizeUserName(final String plainName) {
+        final BidiFormatter bidi = BidiFormatter.getInstance();
+
+        if (plainName.startsWith("@")) {
+            return "@" + bidi.unicodeWrap(plainName.substring(1));
+        } else {
+            return bidi.unicodeWrap(plainName);
+        }
+    }
+
     public static org.schabi.newpipe.extractor.localization.Localization getPreferredLocalization(
             final Context context) {
         return org.schabi.newpipe.extractor.localization.Localization