Add the ClientConsensusState definition in ibc mock proto

[ancazamfir]

Summary

Add the ClientConsensusState definition in ibc mock proto file
https://github.com/informalsystems/ibc-rs/blob/master/proto/definitions/mock/ibc.mock.proto

Then fix impl TryFromRaw for AnyConsensusState for mock consensus state.

Problem Definition

Proposal

---

For Admin Use

• Not duplicate issue
• Appropriate labels applied
• Appropriate contributors tagged
• Contributor assigned/self-assigned

[ancazamfir]

Fixed with #247