Add support for Microsoft.Extensions.Configuration

[m-nash]

Initial prototype to support Microsoft.Extensions.Configuration and Microsoft.Extensions.DependencyInjection

Sample usage with configuration only

        ConfigurationManager config = new();
        config.AddJsonFile("appsettings.json", optional: false);
        config.AddEnvironmentVariables();

        ClientConnection openAIConnection = config.GetConnection("OpenAIClient");
        ClientConnection azureOpenAIConnection = config.GetAzureConnection("AzureOpenAIClient");

        ChatClient openAIChatClient = openAIConnection.CreateChatClient();
        ChatClient azureOpenAIChatClient = azureOpenAIConnection.CreateChatClient();

        Console.WriteLine(openAIChatClient.CompleteChat("Hello world!").Value.Content[0].Text);
        Console.WriteLine(azureOpenAIChatClient.CompleteChat("Hello world!").Value.Content[0].Text);

Sample usage with dependency injection

        IHost host = Host.CreateDefaultBuilder()
            .AddKeyedOpenAIChatClient("oai", "OpenAIClient")
            .AddKeyedOpenAIChatClient("aoai", "AzureOpenAIClient")
            .Build();

        ChatClient openAIChatClient = host.Services.GetRequiredKeyedService<ChatClient>("oai");
        ChatClient azureOpenAIChatClient = host.Services.GetRequiredKeyedService<ChatClient>("aoai");

        Console.WriteLine(openAIChatClient.CompleteChat("Hello world!").Value.Content[0].Text);
        Console.WriteLine(azureOpenAIChatClient.CompleteChat("Hello world!").Value.Content[0].Text);

[github-actions]

API Change Check

APIView identified API level changes in this PR and created the following API reviews

Azure.Core
Azure.Identity
Azure.ResourceManager
System.ClientModel

[KrzysztofCwalina]

since these apis are in SCM, should these be just static Create methods on ClientConnection, or maybe even ClientConnection ctor? This way we don't need to add a new type (the config extensions)

[KrzysztofCwalina]

I wonder if we dont need an optional parameter called "format" (or something like that). This would allow us to add support for all the combinations in aspire. Unless we are fine with probing all the formats.

[KrzysztofCwalina]

I wonder if we should not give it a nice name: GetClientConnection. This method will work with both Azure and non-Azure scenarios. I even wonder if we could call the SCM variant of the method the same and use the new C# attribute (overload priority) to resolve ambiguity