Testbed, UnitTests, Benchmark require git recursive clone

[louis-langholtz]

Expected/Desired Behavior or Experience:

Project's CMake configuration can build these application components without having needed to have done a git recursive clone of the repo or even a git clone of it. Downloading the ZIP file should be enough.

Actual Behavior:

Trying to configure CMake with the building of these application components turned on fails with CMake errors and build errors if the source code wasn't recursively cloned.