Handle rich bot message fallback for macOS

[ohld]

What

Adds compatibility parsing for newer Telegram TL constructors seen by the macOS client when loading Bot API rich messages, including richMessage, newer poll/media/update variants, reply headers, keyboard buttons, stories, gifts, and topic message containers.

The goal is graceful fallback rendering instead of leaving bot rich messages as unsupported media placeholders.

Why

Recent bot messages using newer rich formatting can be delivered to this older macOS client as unsupported media. When the client later requests the rich message payload, parsing may fail on newer TL constructors such as messageMediaPoll#773f4e66, poll#966e2dbf, pollResults#ba7bb15e, and updateMessagePoll#d64c522b.

Notes

• messages.getRichMessage is tried before the older unsupported-media refresh methods.
• RichMessage blocks are converted into a plain-text fallback, preserving readable text when native rich block rendering is absent.
• Newer constructor wrappers consume extra fields and map back to existing model cases where possible.

Verification

• swift build in submodules/TelegramApi: passed.
• macOS app rebuild through the parent TelegramSwift workspace: passed.
• Fresh Telegram Dev RichTest log for https://t.me/ohld_chat/35423 after restart:
  • This message is not supported: 0
  • messageMediaUnsupported: 0
  • d64c522b: 0
  • 49e91f2a: 0
  • 7600b9d3, baf39d8b, 773f4e66, 966e2dbf, ba7bb15e: 0

Local test artifact from parent workspace:
/Users/ohld/Documents/GitHub/TelegramSwift/artifacts/Telegram-Dev-RichTest.dmg
SHA256: a4a572cbd789f140555753ffc436c686ba7fa7255b720c8e435dfca132af05a3