How to handle enter key in NSTextField

Issue #635

textField.delegate = self

NSTextFieldDelegate

func control(_ control: NSControl, textView: NSTextView, doCommandBy commandSelector: Selector) -> Bool {
    if (commandSelector == #selector(NSResponder.insertNewline(_:))) {
        // Do something against ENTER key
        print("enter")
        return true
    } else if (commandSelector == #selector(NSResponder.deleteForward(_:))) {
        // Do something against DELETE key
        return true
    } else if (commandSelector == #selector(NSResponder.deleteBackward(_:))) {
        // Do something against BACKSPACE key
        return true
    } else if (commandSelector == #selector(NSResponder.insertTab(_:))) {
        // Do something against TAB key
        return true
    } else if (commandSelector == #selector(NSResponder.cancelOperation(_:))) {
        // Do something against ESCAPE key
        return true
    }

    // return true if the action was handled; otherwise false
    return false
}