Add CodeCargo.NatsHybridCache package

[caleblloyd]

Introduces NatsHybridCacheExtensions which provides extension methods for integrating NATS with Microsoft's HybridCache.

1. AddNatsHybridCache Method

   • Registers NATS distributed cache with an IServiceCollection
   • Configures HybridCache to use the serializer registry from the NATS connection
   • Supports optional keyed INatsConnection instances

2. AddNatsHybridCacheSerializerFactory Method

   • Registers an IHybridCacheSerializerFactory created from an INatsSerializerRegistry

Rename root namespace of DistributedCache back to CodeCargo.NatsDistributedCache and new package is CodeCargo.NatsHybridCache

• Helps avoid namespace collisions when using HybridCache