[Worker] Log. how long it takes to quitAndWait a worker

* sometimes the shutdown sequence of swift takes extremly long, this is to identify which workers are affected
* reduced "wait time"
* function so each worker can have its own "wait" time
* for a worker there are 2 "waits", the quitAndWait of the worker and the wait of CRegularThread (dtor)


Originally Ref T145, T647

src/blackmisc/worker.h

@@ -327,6 +327,13 @@ namespace BlackMisc
         //! Called when the thread is finished.
         virtual void cleanup() {}
 
+        //! Called before quit is called
+        //! \remark can be used to "clean things up" or request work functions to stop
+        virtual void beforeQuit() noexcept {}
+
+        //! Wait time for quitAndWait, 0 means not waiting
+        virtual unsigned long waitTimeoutMs() const { return 15 * 1000; }
+
         QTimer m_updateTimer { this }; //!< timer which can be used by implementing classes
 
     private: