Translate tuple to Menu object to keep consistency with constructor when set tuple value to menu

[pmh905001]

User can pass tuple object as menu in constructor of Icon, so the value of menu.setter should support to be tuple object. This can fix the issue that invisible menu item is displayed after updating menu. For example:

import pystray
from PIL import Image
from pystray import MenuItem

def checked_item(icon, item):
icon.menu = (
MenuItem(text='item 2', action=checked_item),
MenuItem(text='Invisible item', action=lambda icon, item: print('default action'), default=True, visible=False),
)

pystray.Icon(
name="icon_name",
icon=Image.open(r'icon.png'),
title='app_name',
menu=(
MenuItem(text='item 1', action=checked_item),
MenuItem(text='Invisible item', action=lambda icon, item: print('default action'), default=True, visible=False),
)
).run()

you would see that 'Invisible item' displayed in menu.