HttpStreamingRequest reads the headers again for each loop

[KeithHenry]

In a while ((line = await reader.ReadLineAsync()) != null) loop the response headers are read each time:

OpenAI-API-dotnet/OpenAI_API/EndpointBase.cs

Lines 352 to 364 in 97fb71b

	try
	{
	res.Organization = response.Headers.GetValues("Openai-Organization").FirstOrDefault();
	res.RequestId = response.Headers.GetValues("X-Request-ID").FirstOrDefault();
	res.ProcessingTime = TimeSpan.FromMilliseconds(int.Parse(response.Headers.GetValues("Openai-Processing-Ms").First()));
	res.OpenaiVersion = response.Headers.GetValues("Openai-Version").FirstOrDefault();
	if (string.IsNullOrEmpty(res.Model))
	res.Model = response.Headers.GetValues("Openai-Model").FirstOrDefault();
	}
	catch (Exception e)
	{
	Debug.Print($"Issue parsing metadata of OpenAi Response. Url: {url}, Error: {e.ToString()}, Response: {resultAsString}. This is probably ignorable.");
	}

These don't change and are in a try-catch that is expensive when a throw happens.

[OkGoDoIt]

good catch, fixing now