Create test cases for all token modes

[dmohns]

As we started working on porting the OpenPAYGO library to other programming languages it became apparent that need a good way to confirm the interop between those.

Ideally, we create a (potentially very long) JSON files which covers all token cases and acts as a source of truth. All libraries (including this one) should be equipped with CI test suit that runs tests against the provided JSON file.