Function moras::menu::file::close_checker

pub fn close_checker(window: &Window, name: &str, tab: &mut Tab)

Check if the file is dirty, if so, display a dialog to ask user to save the file or not. If user choose to save, save the file and then close the tab. If user choose not to save, close the tab directly.

This function will emit a front_close_tab event to the window.