Implemented basic functionality with an issue: no signature deduplication. LC<->TC communication differs from requested. Hashmap search seems buggy. Dubious tests. No scripts.

More info on issues: https://contest.com/docs/TrustlessBridgeChallengeAssessment

potential issues:
1. task requires scripts, but this solution doesn't have them (they are not finished)
2. lite-client sends 'ok' message back to user with "CARRY_ALL_BALANCE" flag, contract will remain with 0 balance and will be destroyed? or it works differently?
3. lite-client and transaction-checker are tightly depend on each other in this solution, then why not just merge them in one smart contract?
4. also transaction checker saves validator sets, what's the point if you send block to lite-client anyway

also deployed smart contracts on testnet doesn't have success and failed messages example

You don't check duplicates from signatures. Attacker can use one signature several times.

In Transaction-checker smart-contract you don't check that `tr_proof` and `block_proof` has the same hash.

Bug in hm_label::parse. You always ignore v. But if v == 0, than s must be zero.