gtk4: Initial app menu implementation
Breaks FREECIV_NDEBUG build
menu.c:2105:55: error: 'ui_builder' undeclared (first use in this function)
Reply To cazfi
Breaks FREECIV_NDEBUG build menu.c:2105:55: error: 'ui_builder' undeclared (first use in this function)
Fixed
Some work towards app menu in gtk4-client. Mostly lower level changes, but includes "Game" menu with some entries as an example and testing ground.