feat(plugins): add poll, react, boosts, and bulk ops plugins
- poll: create polls and quizzes via /poll and /quiz with pipe-separated options; uses native Telegram poll API with quiz mode support
- react: reply to messages with /react <emoji> to set reactions via set_message_reaction API; auto-deletes command message
- boosts: view user boost count in chat, hooks on_chat_boost to send notification when chat receives a new boost
- bulkops: /forward and /copy commands to forward/copy replied messages to target chats using forward_messages/copy_messages API