Add Chain Support for Ethereum Classic (61), the largest PoW Smart Contract Blockchain

[chris-mercer]

Feature Suggestion
Add support for Ethereum Classic, Chain 61.
Add support for Mordor Testnet, Chain 63.

Impact
Support Ethereum Classic will allow Hbot users to connect the mature CEX ETC/USD markets with them immature DEX ecosystem on Ethereum Classic

Additional context
Ethereum Classic is now the largest PoW EVM. It is regularly doing over $100M in daily volume on the low side and commonly over $1B in daily volume. This puts ETC/USD as one of the longest and best performing markets in the blockchain space. ETC markets are widely supported on all major CEX. In addition to this, DeFi protocols are turning on to replicate the DeFi summer activity we saw on the ETH chain in 2019. Example: https://v3.etcswap.org

[fengtality]

Ethereum Classic can be now added as an new Ethereum network, but it should only be added when there's a DEX connector updated to v2.8 that uses it.