Change agents to new JS API

[DanWahlin]

This pull request enhances the JavaScript QuickStart sample by improving the setup instructions, updating dependencies, and refactoring the code for better modularity and functionality. Key changes include updating the README for clearer environment setup, upgrading package dependencies, and refactoring the quickstart.js script to align with the latest Azure AI SDK conventions.

Documentation Improvements:

• Updated README.md to provide clearer and more detailed instructions for setting up the environment, including downloading configuration files, setting environment variables, and installing dependencies.

Dependency Updates:

• Upgraded dependencies in package.json and package-lock.json, including updates to @azure/ai-agents, @azure/ai-projects, @azure/msal-browser, @azure/msal-common, @azure/msal-node, and other libraries to their latest versions for improved functionality and compatibility. [1] [2] [3]

Code Refactoring:

• Refactored quickstart.js to use the updated Azure AI SDK client methods, improving clarity and aligning with the latest API structure. Changes include:
  • Replacing createAgent, createThread, and createMessage with their corresponding namespaced methods like agents.createAgent and agents.threads.create. [1] [2]
  • Enhanced iteration for listing messages using async iterators.
  • Modularized file upload and vector store creation logic.

Script Enhancements:

• Modified the start script in package.json to include the --no-deprecation flag, suppressing deprecation warnings during execution.

Minor Improvements:

• Updated the ToolUtility import in quickstart.js for better modularity and removed unused imports.