[feature] Event stream by chain

Create chain specific event streams. This makes it so that midgard can pull the events on a per chain level. The reason why this is helpful is because events are only displayed until they are completed, and they are always displayed in order. So if an event takes 10min to complete (like BTC), then it won't get other chain events (like BNB) until the BTC one completes. This can put midgard pool balances off by a significant margin consistently.

In addition, this makes it's more efficient for future Mjölnir nodes to subscribe per chain (ie Mjölnir nodes only care about the pools they have coins for)