Code is splitted in 4 different libraries, following the layout of
functions and files of the go implementation
- Ops -> go/ops.go
- Proof -> go/proof.go
- Compress -> go/compress.go
- Ics23 -> go/ics23.go

Missing parts of the current implementation:
- sha512 hash option: solidity does not have built-in function for this
hash. A solidity implementation would be utterly inefficient and very
costly (gas-wise)
- compress functions: this implementation is meant be used for
verification, not for proof generation
- ProofSpec for tendermint and iavl definition: again, this
implementation is just to verify, not to generate
- Decompress functions are present but not working: currently
investigating a potention buf in the protobuf runtime
- Batch verification functions are temporarily disabled due to above

Changing the return values of functions throughout the libraries to
avoid using ``require`` and ``revert``. Function callers will receive an
enum encoding the Error

Separating Mock contracts from libraries