Add counter on comment form

lib/utils/ui_utils.dart

@@ -153,3 +153,13 @@ Future<bool> showConfirmDialog({
 
   return result != null && result;
 }
+
+/// Smart [InputCounterWidgetBuilder] that show text limit only when some
+/// text has already been entered by the user
+Widget smartInputCounterWidgetBuilder(
+  BuildContext context, {
+  @required int currentLength,
+  @required int maxLength,
+  @required bool isFocused,
+}) =>
+    currentLength > 0 ? Text("$currentLength/$maxLength") : Container();