Add Support for Azure Cognitive Services

[petergoldstein]

Currently Asimov uses the OpenAI endpoints by default. The base URI can be overridden, which allows the use of simple proxying services like Helicone. But Asimov does not yet support the use of the Azure Cognitive Services version of OpenAI. To get that working there are several changes required:

• Add API type as a configurable parameter
• Add API version with appropriate default behavior
• Update authorization header behavior to account for API type (OpenAI/Azure AD vs. Azure)
• Update URI construction to account for API type (OpenAI vs. Azure/Azure AD)
• Add Azure-only support for the deployments endpoints
• Restrict unsupported OpenAI endpoints when the API type is Azure

This effort is currently underway.