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/bittorrent/dbresumedatastorage.h

@@ -34,8 +34,6 @@
 #include "base/utils/thread.h"
 #include "resumedatastorage.h"
 
-class QThread;
-
 namespace BitTorrent
 {
     class DBResumeDataStorage final : public ResumeDataStorage
@@ -61,8 +59,6 @@ namespace BitTorrent
         void updateDB(int fromVersion) const;
         void enableWALMode() const;
 
-        Utils::Thread::UniquePtr m_ioThread;
-
         class Worker;
         Worker *m_asyncWorker = nullptr;