Move XINDEX files to separate subdirectory

To prepare for a new set of Package based tests, move the location that
the XINDEX files are configured to into a directory within the Testing
folder.

Update the CMake script to use the new location for the Python files.

OSEHRA-Id: http://issues.osehra.org/browse/OAT-126
Change-Id: I0a3a0cf6a4a96b8cc0c9d1309256b5447e5b4bd0