Motivation and Context

Add support for Azure AI Agents:

• https://github.com/Azure/azure-sdk-for-net/tree/main/sdk/ai/Azure.AI.Projects/src/Custom/Agent
• https://learn.microsoft.com/en-us/azure/ai-services/agents/

Fixes: #10114

Description

• Adds AzureAIAgent type in a new project/package
• Maintains parity with OpenAIAssistantAgent
• Supports Azure specific tool offerings

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄