#5306 HIP-4 Part 2: Add sushiswap connector to Gateway

Add Sushiswap connector to the gateway: https://app.sushi.com/swap

• The Sushiswap sdk is similar to the Uniswap sdk.
• Created the Sushiswap connector and made it usable via amm routes.
• Add a function for fetching pair data in the connector to replace the Fetcher class that was removed from the sdk.

Link: https://github.com/hummingbot/hummingbot/pull/5306