change azure engine config to modelMapper (#306)

* change azure engine config to azure modelMapper config

* Update go.mod

* Revert "Update go.mod"

This reverts commit 78d14c58f2a9ce668da43f6adbe20b60afcfe0d7.

* lint fix

* add test

* lint fix

* lint fix

* lint fix

* opt

* opt

* opt

* opt

chat_stream.go

@@ -46,7 +46,7 @@ func (c *Client) CreateChatCompletionStream(
 	}
 
 	request.Stream = true
-	req, err := c.newStreamRequest(ctx, "POST", urlSuffix, request)
+	req, err := c.newStreamRequest(ctx, "POST", urlSuffix, request, request.Model)
 	if err != nil {
 		return
 	}