[Feature]: Support Telegram Bot API 10.1 Rich Messages and rich draft streaming

#44428 Investigating P3 comp/gateway

[Feature]: Support Telegram Bot API 10.1 Rich Messages and rich draft streaming

This issue proposes adding support for Telegram Bot API 10.1's new Rich Messages (headings, lists, tables, LaTeX, etc.) to the Telegram gateway, replacing the current plain/MarkdownV2 message streaming approach.