This adds the OriginalRequest to the Response object, when using thedefault HttpCLientMediator.
This in turn allows the exact data of the original request to be pulled from an ApiException to help with error logging from within a consuming client, which is not something that afaik has been available up to now.
I've only been able to find deatils of the original  which does not contain any headers, query or request payload
Pull OriginalRequest propety up to base ApiException to enable OriginalRequest to be accessible in all ApiExceptions, this then allows the  method to still show the originalRequest if a WebException occurs that has no internal response
Change naming of var to response
Set OriginalRequest to be immutable
Remove Uri property from ApiException as it has been replaced with full request
Alter failing test to assert only that track count is >= 1 as the important assert is on the following line
Added ApiException Uri parameter back in and marked it Obsolete to prevent major version change
Merge pull request #158 from gregsochanik/original-request-in-response

This adds the `OriginalRequest` to the `ApiException` object,