debugger: more of the RunControl refactoring

Pass output through the RunControl instead of the DebuggerManager.

src/plugins/debugger/script/scriptengine.h

@@ -104,8 +104,6 @@ private:
     void updateLocals();
     void updateSubItem(const WatchData &data);
 
-    Q_SLOT void showDebuggerOutput(int channel, const QString &m);
-
 private:
     friend class ScriptAgent;