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.cpp

@@ -123,6 +123,7 @@ AutoDownloader::AutoDownloader(IApplication *app)
                .arg(fileName.toString(), errorString), Log::CRITICAL);
     });
 
+    m_ioThread->setObjectName("RSS::AutoDownloader m_ioThread");
     m_ioThread->start();
 
     connect(app->addTorrentManager(), &AddTorrentManager::torrentAdded