Integrate RedisJSONRpcServer

[VIPO777]

Summary
Research NDI’s RedisJSONRpcServer and integrate a compatible Redis JSON-RPC bridge into NdGameSdk to call native game functions via Redis Pub/Sub. Also ship a small helper tool that launches a locally preconfigured Redis server.

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Goals

• Mirror NDI behavior: SUBSCRIBE game.%s.%s.rpc.publish, parse JSON-RPC, dispatch to native handlers, publish replies, and append history entries.
• Provide a clean C++ API inside NdGameSdk for registering RPC methods that safely marshal work to the game/main thread.
• Deliver a cross-platform Redis client implementation (Windows-first), plus a tiny “Redis host” helper that runs a locked-down local Redis.
• Possibility of integrating modding tools for real-time update and hot-reload operations.