Adding vtk_tests() declarative macro.
Adding vtk_tests() declarative macro.

- This macro help in eliminating a lot of boiler plate code for
most */Testing/Cxx/CMakeLists.txt.
- All we now need to do do is simply declare
the tests inside vtk_tests().
- Note that that MPI tests are not supported by this macro and need to use
add_test_mpi() macro instead.

Change-Id: I7df388dc98fb2fff7c9289af8a8fc906ff7ac0a5

candy7393/VTK,candy7393/VTK,gram526/VTK,biddisco/VTK,hendradarwin/VTK,keithroe/vtkoptix,collects/VTK,gram526/VTK,sumedhasingla/VTK,mspark93/VTK,berendkleinhaneveld/VTK,aashish24/VTK-old,gram526/VTK,SimVascular/VTK,ashray/VTK-EVM,keithroe/vtkoptix,ashray/VTK-EVM,candy7393/VTK,biddisco/VTK,mspark93/VTK,johnkit/vtk-dev,gram526/VTK,jmerkow/VTK,sumedhasingla/VTK,sankhesh/VTK,msmolens/VTK,SimVascular/VTK,msmolens/VTK,demarle/VTK,biddisco/VTK,sumedhasingla/VTK,jmerkow/VTK,johnkit/vtk-dev,sumedhasingla/VTK,demarle/VTK,hendradarwin/VTK,jmerkow/VTK,collects/VTK,berendkleinhaneveld/VTK,hendradarwin/VTK,keithroe/vtkoptix,sankhesh/VTK,biddisco/VTK,biddisco/VTK,biddisco/VTK,keithroe/vtkoptix,berendkleinhaneveld/VTK,sankhesh/VTK,demarle/VTK,candy7393/VTK,mspark93/VTK,collects/VTK,hendradarwin/VTK,hendradarwin/VTK,jmerkow/VTK,gram526/VTK,SimVascular/VTK,johnkit/vtk-dev,mspark93/VTK,biddisco/VTK,mspark93/VTK,sankhesh/VTK,sankhesh/VTK,hendradarwin/VTK,mspark93/VTK,SimVascular/VTK,sankhesh/VTK,aashish24/VTK-old,ashray/VTK-EVM,sumedhasingla/VTK,msmolens/VTK,mspark93/VTK,berendkleinhaneveld/VTK,demarle/VTK,aashish24/VTK-old,ashray/VTK-EVM,SimVascular/VTK,berendkleinhaneveld/VTK,ashray/VTK-EVM,johnkit/vtk-dev,gram526/VTK,gram526/VTK,msmolens/VTK,demarle/VTK,keithroe/vtkoptix,jmerkow/VTK,keithroe/vtkoptix,berendkleinhaneveld/VTK,gram526/VTK,SimVascular/VTK,keithroe/vtkoptix,msmolens/VTK,candy7393/VTK,sumedhasingla/VTK,candy7393/VTK,msmolens/VTK,candy7393/VTK,aashish24/VTK-old,collects/VTK,jmerkow/VTK,sankhesh/VTK,demarle/VTK,hendradarwin/VTK,sumedhasingla/VTK,jmerkow/VTK,SimVascular/VTK,collects/VTK,SimVascular/VTK,collects/VTK,jmerkow/VTK,ashray/VTK-EVM,ashray/VTK-EVM,sumedhasingla/VTK,sankhesh/VTK,mspark93/VTK,ashray/VTK-EVM,johnkit/vtk-dev,msmolens/VTK,keithroe/vtkoptix,berendkleinhaneveld/VTK,msmolens/VTK,demarle/VTK,aashish24/VTK-old,candy7393/VTK,aashish24/VTK-old,demarle/VTK,johnkit/vtk-dev,johnkit/vtk-dev