lambdaurl Wrap is not proxying `LambdaFunctionURLRequest.Cookies`

[nguyengg]

Is your feature request related to a problem? Please describe.
The Wrap function from https://github.com/aws/aws-lambda-go/blob/main/lambdaurl/http_handler.go#L105 creates an http.Request from an events.LambdaFunctionURLRequest. I don't see any references to proxying the original request's cookies similar to what aws-lambda-go-api-proxy does:

	for _, cookie := range req.Cookies {
		httpRequest.Header.Add("Cookie", cookie)
	}

This is a deal-breaker for me because my stream handlers rely on cookies

Describe the solution you'd like
Copy and paste that code block (I'll do this with a PR after creating this issue).

Describe alternatives you've considered
I don't think this module would like to take a dependency on aws-lambda-go-api-proxy so copying and pasting may be best.

Additional context
None.

[nguyengg]

From what I can tell in https://github.com/aws/aws-lambda-go/blob/main/lambdaurl/testdata/function-url-request-with-headers-and-cookies-and-text-body.json and https://github.com/aws/aws-lambda-go/blob/main/lambdaurl/http_handler_test.go#L51, looks like only cookies in the LambdaFunctionURLRequest.Headers["cookie"] are proxied to the resulting http.Request. This will break use cases where users rely on LambdaFunctionURLRequest.Cookies instead.

Will AWS Lambda Function URL handlers always receive identical .Cookies and .Headers["cookie"] values?