4.15.0

4.15.0

• Add support for item_reference content type in Add-RealtimeSessionItem.
• Allow -MaxTokens and -MaxCompletionTokens parameters to accept negative values.
  This is for compatibility APIs; the official OpenAI API returns an error for values less than 1.
• Implement new api exception types.
  • PermissionDeniedException
  • ConflictException
  • UnprocessableEntityException
• Minor improvements.