Add support for NATS-KV (key-value) store

[vaidehiadhi]

Pull Request Template

Description:

• Support for NATS Key-Value store as a new storage option in GoFr. The implementation provides a simple yet robust key-value storage solution using NATS JetStream.
• Closes issue Add support for NATS-KV (key-value) store Add support for NATS-KV (key-value) store #1038

Breaking Changes (if applicable):

None.

Additional Information:

• Dependencies Added:

github.com/nats-io/nats.go: Core NATS client library

Usage Example

// Initialize NATS KV client
natsClient := nats.New(nats.Configs{
    Server: "nats://localhost:4222",
    Bucket: "my-bucket",
})

// Add to GoFr app
app.AddKVStore(natsClient)

// Use in handlers
value, err := ctx.KVStore.Get(ctx, "my-key")

To Start NATS server with JetStream:
docker run -d --name nats-server -p 4222:4222 nats:latest --js

Checklist:

• I have formatted my code using goimport and golangci-lint.
• All new code is covered by unit tests.
• This PR does not decrease the overall code coverage.
• I have reviewed the code comments and documentation for clarity.

Thank you for your contribution!