Update MEAI Template to integrate ConversationId for stateful chat systems

[jeffhandley]

The MEAI project template doesn't utilize ConversationId.

For stateful chat systems, we could detect the ConversationId and apply that with further messages. This would avoid issues related to history management and make the exchanges more efficient. This would also unblock scenarios such as uploading images as they wouldn't need to be re-uploaded on each interaction.

[ericstj]

Here's what I did around this when prototyping imageGen tool:

        var chatMessages = chatOptions.ConversationId is null
            ? messages
            : [userMessage];

        var response = await ChatClient.GetResponseAsync(chatMessages, chatOptions);

        chatOptions.ConversationId = response.ConversationId;

This worked for me in general for having a stateful conversation with the responses client. We might need to double check that every chat client that exposes a value for ConversationId on the response supports such behavior.

[jozkee]

This worked for me in general for having a stateful conversation with the responses client

I suggested @ViveliDuCh that for openai and azureopenai providers we could switch to a responses client; one problem with that is that is marked as experimental to this day so we would have to add a suppression to the template.

She will also be investigating if its possible to have stateful conversations with ollama and ghmodels.