Issue 6180 - use ABP_TEXT everywhere in order to let String be a UTF-8 string

compiled/subscription/UserDefinedSubscription.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 75 matching lines @@
         *filter.get(), this, pos);
   }
   return true;
 }
 
 OwnedString UserDefinedSubscription::Serialize() const
 {
   OwnedString result(Subscription::Serialize());
   if (!IsGeneric())
   {
-    result.append(u"defaults="_str);
+    result.append(ABP_TEXT("defaults="_str));
     if (mDefaults & FilterCategory::BLOCKING)
-      result.append(u" blocking"_str);
+      result.append(ABP_TEXT(" blocking"_str));
     if (mDefaults & FilterCategory::WHITELIST)
-      result.append(u" whitelist"_str);
+      result.append(ABP_TEXT(" whitelist"_str));
     if (mDefaults & FilterCategory::ELEMHIDE)
-      result.append(u" elemhide"_str);
-    result.append(u'\n');
+      result.append(ABP_TEXT(" elemhide"_str));
+    result.append(ABP_TEXT('\n'));
   }
   return result;
 }