Add Local Caching Mechanism to Improve Chat Load Performance in CometChat React Native UI Kit

Opening a conversation in the CometChat React Native UI Kit currently triggers a full reload of messages from the server each time, resulting in slower load times and a less responsive user experience.

In a real-time chat application, users expect conversations to open instantly with previously viewed messages readily available. The lack of a local caching mechanism leads to repeated network calls and unnecessary data fetching, even for recently accessed chats.

Introducing a local caching mechanism to store recent conversations and messages on the device would allow chats to load instantly while syncing with the server in the background. This would significantly improve performance, reduce latency, and provide a smoother and more seamless user experience, especially in low or unstable network conditions.