fix: Refactor processedMessages to improve performance and fix key issue

[Mirza-Samad-Ahmed-Baig]

This pull request addresses these issues by:

• Refactoring the processedMessages hook to be more efficient.
• Creating a new utility function generateToolCallId to generate stable and unique IDs for tool calls.
• Using the new utility function to generate keys for tool calls in the processedMessages hook.

Benefits:

• Improved performance: The chat interface will now be more responsive, especially for long conversations.
• Improved stability: The use of stable keys for tool calls will prevent issues with React's reconciliation
  process.