AzureOpenAI client should be exported by @langchain/openai

[msalafia]

I don't know if a discussion is a proper way to ask for this, but issue seems available for bugs only.

The index file for the @langchain/openai export only the OpenAI client, but i think this must be done for Azure client too. Since, as in my case, this is blocking me to write my own version of a class using the AzureClient without installing the openai package (which i cannot due to dependency versions clash, i don't want to in any case).

This is the first row of the index.ts file

export { OpenAI as OpenAIClient, type ClientOptions, toFile } from "openai";

I reaaly think that AzureOpenAI as AzureOpenAIClient, should be exported too.