This struct defines a single action.
It is for use with [method@Gio.ActionMap.add_action_entries].
The order of the items in the structure are intended to reflect frequency of use. It is permissible to use an incomplete initialiser in
order to leave some of the later values as `NULL`. All values after name are optional. Additional optional fields may be
added in the future.
See [method@Gio.ActionMap.add_action_entries] for an example.