start removal of six and improve type annotation (#607)

* fix unfinished Python2 -> 3 translation
* remove some six usage
* annotate
* fix regression in Six removal
* mypy: self.enf is always defined
* fix return type of cups.py
* Usb idVendor/idProduct are integers
* self.default_args is always defined
* tweak usb_args, PEP589 is better
* lp.py: reassure mypy
* correctly cast call to CashDrawerError()
* update CUPS test
* add missing close() method in metaclass
* document a bug in typeshed
* query_status() returns bytes as seen in constants.py
* remove more SIX usage
* test examples too
* remove type comment where type is annotated
* adapt behavior of cups printer to match other implementations

---------

Co-authored-by: Patrick Kanzler <dev@pkanzler.de>
Co-authored-by: Patrick Kanzler <4189642+patkan@users.noreply.github.com>

examples/weather.py

@@ -18,8 +18,8 @@ import calendar
 import json
 import os
 import time
-import urllib
 from datetime import datetime
+from urllib.request import urlopen
 
 from escpos.printer import Usb
 
@@ -93,7 +93,7 @@ url = (
     + LONG
     + "?exclude=[alerts,minutely,hourly,flags]&units=si"
 )  # change last bit to 'us' for Fahrenheit
-response = urllib.urlopen(url)
+response = urlopen(url)
 data = json.loads(response.read())
 
 printer.print_and_feed(n=1)