Add BlockProof examples

[pyAndr3w]

Idea

Provide a minimal BlockProof demo that covers two broad scenarios:

1. State proof
   • Jetton-wallet proof (re-use logic from tact-lang/dex).
   • Direct jetton price proof from TON DEX pools (oracle-free).
   • [Jetton] Wallet balance proof.
   • NFT ownership proof.
2. Transaction proof
   • Verify that a given transaction really happened (like in Trustless Bridge).

Potential Benefits

• Trust-minimised composability inside DeFi protocols.
• Fewer external dependencies (no off-chain price or state oracles).

References

• JettonMaster state-proof for discovery Jetton Wallet Address in Jetton Vault (tact-lang/dex). -> feat: Added possibility to proof JettonMaster state for initializing Jetton Vault dex#79
• Trustless Bridge Contest -> https://contest.com/ton-trustless-bridge