Enhancement: Add support for timeout greater than 60 seconds.

[iupchris10]

I had to stop using ModernHttpClient because I discovered that the timeout I set on my HttpClient (which is greater than 60 seconds) is not applied to the native NSUrlSession / OkHttp request. It appears that ModernHttpClient is using the default 60 second timeout, which is sadly not sufficient for my application, whose server experiences intermittent performance issues but still eventually responds.

It would be nice if a timeout could either be passed into the NativeMessageHandler() constructor, or if the timeout could be plucked off the HttpClient and applied to the native handler.

[mhughey-vent]

I have the same issue.

We have a TLS 1.2 requirement, and we a have to use the NSUrlSession (iOS 7+) configuration setting on HTTP Client implementation section

However, our custom timeout is ignored, so some of our longer running request timeout.

We need a workaround