Add support for Nibiru EthAccount through Codecs Flag

[ertemann]

Nibiru has an upgrade live on testnet which is coming to mainnet soon which introduces their own version of ethaccounts. It is not compatible with the current ethermint and Injective flags that exist in the codecs options, a new one will have to be made.

Someone could follow all these places to implement the flag: https://github.com/search?q=repo%3Acosmos%2Frelayer%20ethermint&type=code

Network registry with the account live: https://github.com/cosmos/chain-registry/blob/2568e2763f1a99e370e972c3418f196ffb965ab5/testnets/nibirutestnet/chain.json#L175

Account type names:

[jtieri]

Thanks for opening the issue. I realized awhile ago that we are in a position where we are going to have to add these changes for every EVM based Cosmos chain and it's not the greatest pattern, but it's been awhile since I've put any thought into a possible better design, or if a different solution is even viable.

I currently don't have the bandwidth for this but if someone else wanted to get a PR opened i'd be more than happy to review that.

If this isn't of interest to you, perhaps @AntiTyping wants to take a stab at this sometime in the future?