[OSS-691] fix: Externally triggered intent fail with Telegram channel

[amitpdev]

Set out_channel as static variable of TelegramInput class. This way, the same TelegramOutput channel instance initiated by Sanic is being used.
This fixes "RuntimeError: asyncio.run() cannot be called from a running event loop" Error.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}