Feature: ZkIcs23

[aeryz]

We want to be able to verify batches of ics23 commitments using zero knowledge. The way of doing is essentially like the following:

Let X hashing be any zk-friendly hashing algorithm:

1. Modify iavl to support X hashing. iavl is being used by the modules as the merkle tree.
2. Modify Cosmos SDK's x/store module to support X hashing. Merkle tree here is being used as the top-level merkle tree where every module's iavl tree root is the value of this merkle tree.
3. Modify ics23 to be able to verify the proofs generated by using X hashing. This is used by Cosmos SDK and is also useful for testing.
4. Implement the necessary circuits to generate proofs (these will be elaborated later in this issue).
5. Modify cometbls light clients and solidity-ics23 to verify membership using zkp.

Ongoing work

We have an ongoing work that supports MiMC:

1. iavl modifications make our iavl tree use MiMC for hashing.
2. x/store modifications make our SimpleMerkle tree use MiMC.

To be continued..

[aeryz]

Not needed anymore as we are gonna do batching