ui: Added file extension UI to project setup

src/lib_gui/qt/window/project_wizzard/QtProjectWizzardContentExtensions.h

@@ -0,0 +1,27 @@
+#ifndef QT_PROJECT_WIZZARD_CONTENT_EXTENSIONS_H
+#define QT_PROJECT_WIZZARD_CONTENT_EXTENSIONS_H
+
+#include "qt/window/project_wizzard/QtProjectWizzardContent.h"
+
+class QtDirectoryListBox;
+
+class QtProjectWizzardContentExtensions
+	: public QtProjectWizzardContent
+{
+	Q_OBJECT
+
+public:
+	QtProjectWizzardContentExtensions(ProjectSettings* settings, QtProjectWizzardWindow* window);
+
+	// QtProjectWizzardContent implementation
+	virtual void populateForm(QGridLayout* layout, int& row) override;
+
+	virtual void load() override;
+	virtual void save() override;
+
+private:
+	QtDirectoryListBox* m_headerList;
+	QtDirectoryListBox* m_sourceList;
+};
+
+#endif // QT_PROJECT_WIZZARD_CONTENT_EXTENSIONS_H