5334: HIP 4 Part 1: Add a Curve connector for Ethereum to Gateway

• Vendorize the curve-js library and make changes necessary in order for it to work with Infura and gateway
• Create the curve connector and make it usable via the amm routes
• Add a condition to hummingbot that assumes Curve allowances are infinite. curve-js handles allowances internally when it performs trades.

Link: https://github.com/hummingbot/hummingbot/pull/5334

HIP 4: https://snapshot.org/#/hbot-ip.eth/proposal/0x0f86d963fc90c972efb78f6ae56b2ae2b189c6d6c8ffa1470aa000251a1163cb