[Azure] Support Realtime API

[deyaaeldeen]

Support Azure Realtime API

In order to do so, this PR adds an azure factory method to OpenAIRealtimeWebSocket and OpenAIRealtimeWS classes that can handle asynchronous operations required during WebSocket connection setup.

Key Changes

1. New azure Method

• Previously, the WebSocket connection was established in the class constructor, which could not handle async operations like fetching Azure AD tokens.
• The new azure method enables asynchronous fetching of the Azure AD token and then pass it to the class constructor.

2. New _getAzureADToken Method in AzureOpenAI

• Adds a _getAzureADToken method in the AzureOpenAI class to provide refreshed Azure AD tokens.