[FR] support telegram api host

[kuyapp]

Is your feature request related to a problem? Please describe.
No

Describe the solution you'd like
pass base_url & base_file_url to python-telegram-bot updater
https://github.com/python-telegram-bot/python-telegram-bot/blob/ade1529986f5b6d394a65372d6a27045a70725b2/telegram/ext/updater.py#L76
so we can connect to telegram via reverse proxy(eg. set reverse proxy on cloudfare workers)

A reverse proxy for Telegram Bot API on Aliyun Function Compute / Cloudflare Workers
https://gist.github.com/ihciah/665fd43b597141fa93a7c85340917835

Describe alternatives you've considered
no

Additional context
no