Bitget V1 API deprecation

[crypto-2042]

Describe the bug
Bitget V1 API deprecation, see : Bitget V1 API deprecation notice
Bitget is not working properly now.

[crypto-2042]

Bitget public WebSocket support in cryptofeed still uses the legacy Spot/Mix v1 endpoints and subscription schema, so public market data is no longer compatible after Bitget migrated these channels to the newer UTA WebSocket API.

Expected upgrade scope

• Migrate Bitget public market data WebSocket connections from legacy:

  • wss://ws.bitget.com/spot/v1/stream
  • wss://ws.bitget.com/mix/v1/stream

  to the newer public endpoint:

  • wss://ws.bitget.com/v3/ws/public

• Update public subscription payload construction from legacy fields:

  • channel
  • instId

  to the new UTA public schema:

  • topic
  • symbol

• Update public instType mapping to the new values used by UTA WebSocket, such as:

  • spot
  • usdt-futures
  • coin-futures
  • usdc-futures

• Adjust public channel mapping:

  • order book remains based on books
  • trades should move from legacy trade to publicTrade
  • ticker/candle topics should be aligned with the new UTA public channel definitions

• Update message routing logic so public messages are dispatched using arg.topic / arg.symbol instead of only arg.channel / arg.instId

• Update order book parsing for the new public depth payload format, including support for v3 field names and sequencing semantics

• Update trade parsing for the new public trade payload structure