Add support for Azure Open AI

[soderlind]

Azure Open AI needs extra fields:

• Azure OpenAI Endpoint (Your Azure OpenAI resource endpoint URL), $endpoint below.
• Azure API Version (e.g., 2024-02-15-preview), $api_version below.
• (Model must be one of the models you've added to your Azure Open AI resource, $model below.)

// Azure OpenAI endpoint format
$url = rtrim( $endpoint, '/' ) . '/openai/deployments/' . $model . '/chat/completions?api-version=' . $api_version;

[saarnilauri]

@soderlind the support for new provider should be first addressesed in the underlying php-ai-client package https://github.com/WordPress/php-ai-client

@JasonTheAdams should this issue be moved to php-ai-client repository?

[JasonTheAdams]

Actually, we're in the process of removing providers from PHP AI Client. We're encouraging folks to create their own plugins for registering providers (e.g. Google provider repo). We don't want to couple any of this with specific providers. We only did it until this point for the convenience of testing. For now, we'll maintain the three provider plugins we had up to this point, but need to figure it if/how we pick more, have a catalog of options, or anything like that.