add max_completions_tokens for o1 series models (#857)

* add max_completions_tokens for o1 series models

* add validation for o1 series models validataion + beta limitations

chat_stream.go

@@ -60,6 +60,10 @@ func (c *Client) CreateChatCompletionStream(
 	}
 
 	request.Stream = true
+	if err = validateRequestForO1Models(request); err != nil {
+		return
+	}
+
 	req, err := c.newRequest(
 		ctx,
 		http.MethodPost,