NO_PROXY not supported

[awdorrin]

While this toolkit supports the HTTP_PROXY and HTTPS_PROXY environment variables, it does not support the NO_PROXY environment variable. In a corporate environment, this can cause issues when your transfer needs to bypass the firewall.

It looks like the completeProxySetup function in awsConnectionParameters.ts should be updated to pull process.env.NO_PROXY into the proxyConfiguration.

I consider the lack of NO_PROXY to be a bug, not a feature, but feel free to move this to a feature request if you disagree.
Thank you.