Unit tests of IBC functionality with new algorithm

[arhag]

Use the Boost unit tests framework and libtester. Look at existing tests like the fork tests to discover how to create two independent instances of a blockchain (the two that will be communicating with each other via IBC) and how chain information can be extracted (though access to controller via libtester) to construct heavy proofs and light proofs.

New contract code to act as IBC verified would need to be committed as a test contract to the Leap code in the appropriate place. Follow the same pattern of committing the WASM/ABI but allowing the source code to build that with the proper CMake variable passed in.

The contract code should NOT focus on:

• transition from old IBC;
• replay protection.

The contract code should be as minimal as possible while satisfying the goal of verifying the new heavy proofs and light proofs of IBC.

[arhag]

We want to also update the tests to use libtester to generate the proofs dynamically.