use separated class files, use hpp header extension, update include model

src/app/browser/header/menu.cpp

@@ -0,0 +1,48 @@
+#include "menu.hpp"
+
+using namespace app::browser::header;
+
+Menu::Menu()
+{
+    set_tooltip_text(
+        TOOLTIP
+    );
+
+    // Build tab submenu
+    auto tab = Gio::Menu::create();
+
+    tab->append(
+        _("New tab"),
+        "app.tab.new"
+    );
+
+    // Build tool submenu
+    auto tool = Gio::Menu::create();
+
+    tool->append(
+        _("Debug"),
+        "app.tool.debug"
+    );
+
+    // Build main menu
+    auto main = Gio::Menu::create();
+
+    main->append_submenu(
+        _("Tab"),
+        tab
+    );
+
+    main->append_submenu(
+        _("Tool"),
+        tool
+    );
+
+    main->append(
+        _("Quit"),
+        "win.quit"
+    );
+
+    set_menu_model(
+        main
+    );
+}