logic: Moved update check setting to preferences and enable automatic update check by default

src/lib_gui/qt/element/QtUpdateCheckerWidget.h

@@ -0,0 +1,21 @@
+#ifndef QT_UPDATE_CHECKER_WIDGET_H
+#define QT_UPDATE_CHECKER_WIDGET_H
+
+#include <QWidget>
+
+class QPushButton;
+
+class QtUpdateCheckerWidget
+	: public QWidget
+{
+public:
+	QtUpdateCheckerWidget(QWidget* parent = nullptr);
+
+private:
+	void checkUpdate(bool force);
+	void setDownloadUrl(QString url);
+
+	QPushButton* m_button;
+};
+
+#endif // QT_UPDATE_CHECKER_WIDGET_H