Add ability to prevent Cut operation through config

[taauntik]

Forum post

Hi bryntum team I am using gantt v5.6.10. I'd like to disabled cut events in gantt. I can set the property Cut to false in the taskMenu configuration. However, it does not prevent users from using Ctrl+X on the keyboard to cut . I found that in the scheduler, users can be prevented from cutting by setting the cutEvent of eventMenu to false. However, eventMenuFeatures is not applicable in Gantt. Can you provide some assistance？

    taskMenu: {
        items:{
            cut:false,
            convertToMilestone: false,
            ...
        }
    }