Azure OpenAI integration support

Here's a patch for the api settings form to allow provider selection. The patch also adds a conditional client based on the service provider.

That said, I'm not working with a typical Azure OpenAI implementation and don't know if this will work for everyone.

If you have any trouble with this patch, share your issues here and maybe I can help.

Modified patch to include correct variable on submit handler

Thanks for posting, I will take a look at this next week. Got backed up on other issues.

@SiliconValet - thanks for the patch! I am getting the below error and I assuming this is because the getModels() function doesn't exist because the model is explicitly declared when creating the client, but most of the sub modules check for that function?

OpenAI\Exceptions\ErrorException: Resource not found in OpenAI\Transporters\HttpTransporter->throwIfJsonError() (line 131 of /var/www/html/vendor/openai-php/client/src/Transporters/HttpTransporter.php).

OpenAI\Transporters\HttpTransporter->requestObject(Object) (Line: 28)
OpenAI\Resources\Models->list() (Line: 86)
Drupal\openai\OpenAIApi->getModels() (Line: 130)