Add WindowSelectionWidget

Refreshes list of windows when widget becomes visible to support widget
caching

plugins/base/utils/window-selection.hpp

@@ -0,0 +1,16 @@
+#pragma once
+#include "filter-combo-box.hpp"
+
+namespace advss {
+
+class WindowSelectionWidget : public FilterComboBox {
+	Q_OBJECT
+
+public:
+	WindowSelectionWidget(QWidget *parent);
+
+protected:
+	void showEvent(QShowEvent *event) override;
+};
+
+} // namespace advss