Refactor OktaSdkBridgeModule for async operations: UI thread blocking

[anujsachan1990]

Refactor OktaSdkBridgeModule for improved asynchronous operations

• Implement ExecutorService for background tasks
• Add Handler for main thread operations
• Refactor methods to use asynchronous pattern:
  • createConfig
  • signIn
  • authenticate
  • (other relevant methods)
• Improve error handling and thread safety
• Add proper resource management with executor shutdown
• Enhance overall code consistency and maintainability
• Update comments to explain new asynchronous approach

This refactor aims to improve performance, responsiveness, and
reliability of the Okta SDK Bridge module while maintaining
compatibility with existing React Native integration.

Addresses issue where certain operations (createConfig, signIn,
authenticate, etc.) could potentially block the UI thread on some
devices, leading to unresponsive app behavior. By moving these
operations to background threads, we ensure a smoother user
experience across all devices, particularly those with limited
resources or slower network connections.

[Brencheva]

Great work!

[testerncoder]

nice