DAP: Show variables for different scopes

Fixed displaying several the same variables.

Change-Id: I848113de3a5e142394fbdb4efd40230f43c2417f
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: hjk <hjk@qt.io>

src/plugins/debugger/dap/dapengine.h

@@ -113,6 +113,8 @@ protected:
     int m_nextBreakpointId = 1;
     int m_currentThreadId = -1;
 
+    bool m_isFirstLayer = true;
+    std::queue<int> m_variablesReferenceQueue;
     WatchItem *m_currentWatchItem = nullptr;
     QList<WatchItem *> m_watchItems;
 };