Fix: spam_time, '429: Too Many Requests'. Feat: autoreply_confirmation, clean_replies, pass_start.

[2naive]

• Antispam is broken due to math operations is not allowed in YAML (when migrated from config.ts). Can't be fixed for backward compatibility because eval('5*60*1000') is not supported in TS. At least config-sample.yaml is fixed.
• '429: Too Many Requests' Telegram error is not handled. Could be reproduced by sending many user messages exceeding bot limits. Fixed with native grammY plugin.
• config.clean_replies allows to send clean messages from support with no footer nor header.
• config.autoreply_confirmation disables autoreplys with 'message received' confirmation
• config.pass_start passes first message from the client to suport team directly

[bostrot]

Thanks for the PR. Looks good :)