qt: Status bar and window fixes

* Fix remember window option
* Status bar pixmaps are now scaled when building with Qt 5

src/qt/qt_main.cpp

@@ -129,7 +129,11 @@ main_thread_fn()
 }
 
 int main(int argc, char* argv[]) {
-    QApplication app(argc, argv);    
+    QApplication app(argc, argv);
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+    app.setAttribute(Qt::AA_UseHighDpiPixmaps);
+    app.setAttribute(Qt::AA_EnableHighDpiScaling);
+#endif
     qt_set_sequence_auto_mnemonic(false);
     Q_INIT_RESOURCE(qt_resources);
     Q_INIT_RESOURCE(qt_translations);