Add name to threads

This help identifying threads when debugging.
The naming scheme is using 'class/function name + variable name'.
Note that the length limitaion is 16 chars on linux. On Windows, the limit is 32767 chars.

PR #21403.

src/base/rss/rss_autodownloader.h

@@ -41,7 +41,6 @@
 #include "base/settingvalue.h"
 #include "base/utils/thread.h"
 
-class QThread;
 class QTimer;
 
 class Application;