#5214 feat / gateway v2

This adds Gateway V2, as previously described in the following Hummingbot blog posts:

https://hummingbot.io/en/blog/gateway-v2-code-architecture https://hummingbot.io/en/blog/gateway-architecture-part-2

Gateway V2 is a major overhaul to the Gateway system, in which Hummingbot uses to communicate with decentralized markets such as Uniswap and Pangolin. Compared to the original Hummingbot Gateway, Gateway V2 adds major improvements to the reliability, user experience and security.

PR Link: https://github.com/hummingbot/hummingbot/pull/5214