The variable is currently used only in Wrappers project and was originally
introduced in 6acfa41f (COMP: Build audio only on windows).

Note that the option CMAKE_CXX_STANDARD is already passed to all
external projects.

This commit partially reverts a543c7d6 (Update C++ to 14) restoring
support for building against C++11.

Implementation of std::make_unique only available with c++14 was originally
introduced in afe976dc (COMP: Clear compilation errors with gcc) and later
moved into imstkMath.h in 60570195 (BUG: Clear compilation errors on Ubuntu)

See https://github.com/oneapi-src/oneTBB/releases/tag/2019_U9

This commit has two purposes:

* update the version of TBB to latest version providing the
  "task_scheduler_init" API deprecated in newer version.

* remove the iMSTK specific logic to look up iMSTK and rely on
  TBB_DIR and associated TBBConfig file.

* rename the external project from "tbb" to "TBB" to be consistent
  with the current naming convention.

This commit renames the project so that its name is consistent with
VTK established convention providing the vtkRenderingOpenVR module.

This commit updates the build system to follow the established CMake
convention.

It also allows the use of iMSTK custom find package in the context of
external project named after the library being integrated and avoid
target name conflicts.

References:

* Double colon in target name means ALIAS or IMPORTED target.

  Source: https://cmake.org/cmake/help/latest/policy/CMP0028.html

* This convention of double-colons gives CMake a hint that the name
  is an IMPORTED target when it is used by downstreams with the
  target_link_libraries() command. This way, CMake can issue a
  diagnostic if the package providing it has not yet been found.

  Source: https://cmake.org/cmake/help/latest/manual/cmake-packages.7.html

REFAC: Update RigidObjectLevelSetCollision for interaction refactor, RigidObjectCollision measureDisplacements node addition