This PR adds support for using Azure Identity's credential classes with Redis Enterprise Entra ID authentication.
The main changes include:
- Add a new factory method createForDefaultAzureCredential to enable using Azure Identity credentials
- Add @azure/identity as a dependency to support the new authentication flow
- Add support for DefaultAzureCredential, EnvironmentCredential, and any other TokenCredential implementation
- Create a new AzureIdentityProvider to support DefaultAzureCredential
- Update documentation and README with usage examples for DefaultAzureCredential
- Add integration tests for the new authentication methods
- Include a sample application demonstrating interactive browser authentication
- Export constants for Redis scopes / credential mappers to simplify authentication configuration
