Add Hyperlinkgrid Entropy Example

[dj-leftway]

This PR adds a working example of using Pyth Entropy for a decentralized lottery grid (Hyperlinkgrid).

Features

• Entropy Integration: Uses Pyth Entropy to generate a secure random number when the grid is full.
• Smart Contracts: Includes HyperlinkgridEntropy.sol and mocks for testing.
• Tests: Full Hardhat test suite verifying the flow.
• Deploy Script: Script to deploy to Base Sepolia.

Check the included README for details on how to run and test.