Add memoization for MonadBlockchainCardanoNodeT queries related to the MonadBlockchain instance

[koslambrou]

Not ready for merge!

Adding a MemoizedCardanoNodeStateQueryT monad transformer, which stores in-memory the responses of the different queries provided by MonadBlockchain. Using the local node's state-query mini protocol is an inefficient way to query information (slow queries, especially if it is spammed with those queries + those queries slow down the other mini-protocols, such as the chain sync mini-protocol).

In its current form, it is a proof of concept to showcase the idea, and see if this is worth adding. Even better if the reviewer has a different viewpoint on how to implement this.

[j-mueller]

This is sensible, to finish it we just need to add protocol parameters to MemoizedCardanoNodeStateQueryResponses. Then we need to refresh the cache periodically (as you said in the comments).

The only question is, how do we detect that a new epoch has started? We could probably just store the start of the next epoch as UTC time, and check against the current time whenever queryProtocolParameters is called.

Or else we say that we discard the MemoizedCardanoNodeStateQueryResponses when we're done building a transaction. That way we don't have to worry about cache expiration, and we still limit the number of actual node queries per transaction to 1.