Fix query handling for relative URLs

When using the function, isAbsolute() from the URI class, this would work incorrectly if there was a query parameter on the URI, so me/files?name=awesome.txt would be considered an absolute URI, instead of a relavative one (which it is).

Change the process in the ApiRequest to keep the path and query separate until we have correctly built out the request, and then appends the query params onto the request.

Fixes #34

Confirmed this works with manual validation in the sample (via Explorer interface), and all test cases continue to pass.