gtk4: Battle Groups menu
Implement Battle Groups functionality via menu, to make it more discoverable. Gtk3(.22)-client and gtk4-client menu systems are too different for both to be handled on the same ticket. This is about gtk4-client.
Implement Battle Groups functionality via menu, to make it more discoverable. Gtk3(.22)-client and gtk4-client menu systems are too different for both to be handled on the same ticket. This is about gtk4-client.