.Net: Feature OpenAI Response Agent

[markwallace-microsoft]

Motivation and Context

Semantic Kernel Agent implementation backed by the Open AI Response API.

Description

Add agent, samples, and tests for OpenAIResponseAgent

Contribution Checklist

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

[Mano1192]

Any luck this will make its way into production this week?

[Mano1192]

Hope to see this integrated this sprint! Pretty big feature for us.

[crickman]

Hope to see this integrated this sprint! Pretty big feature for us.

@Mano1192 We've all be crazy busy on "Build" priorities. Will see if we can move forward with this now.

[markwallace-microsoft]

One failing unrelated integration test

[xUnit.net 00:01:19.38]     SemanticKernel.IntegrationTests.Connectors.OpenAI.OpenAIChatCompletionNonStreamingTests.ChatCompletionWithAudioInputAndOutputAsync [FAIL]
[xUnit.net 00:01:19.38]       Microsoft.SemanticKernel.HttpOperationException : Service request failed.
[xUnit.net 00:01:19.38]       Status: 503 (Service Unavailable)
[xUnit.net 00:01:19.38]       
[xUnit.net 00:01:19.38]       ---- System.ClientModel.ClientResultException : Service request failed.
[xUnit.net 00:01:19.38]       Status: 503 (Service Unavailable)
[xUnit.net 00:01:19.38]       
[xUnit.net 00:01:19.38]       Stack Trace:
[xUnit.net 00:01:19.38]         /home/runner/work/semantic-kernel/semantic-kernel/dotnet/src/Connectors/Connectors.OpenAI/Core/ClientCore.cs(244,0): at Microsoft.SemanticKernel.Connectors.OpenAI.ClientCore.RunRequestAsync[T](Func`1 request)
[xUnit.net 00:01:19.38]         /home/runner/work/semantic-kernel/semantic-kernel/dotnet/src/Connectors/Connectors.OpenAI/Core/ClientCore.ChatCompletion.cs(171,0): at Microsoft.SemanticKernel.Connectors.OpenAI.ClientCore.GetChatMessageContentsAsync(String targetModel, ChatHistory chatHistory, PromptExecutionSettings executionSettings, Kernel kernel, CancellationToken cancellationToken)
[xUnit.net 00:01:19.38]         /home/runner/work/semantic-kernel/semantic-kernel/dotnet/src/SemanticKernel.Abstractions/AI/ChatCompletion/ChatCompletionServiceExtensions.cs(83,0): at Microsoft.SemanticKernel.ChatCompletion.ChatCompletionServiceExtensions.GetChatMessageContentAsync(IChatCompletionService chatCompletionService, ChatHistory chatHistory, PromptExecutionSettings executionSettings, Kernel kernel, CancellationToken cancellationToken)

[markwallace-microsoft]

Merging directly due to integration test instability