Fix paraview crash on mac
For unknown reasons, the catch failed on Mac. So I am switching to the lower level API which avoids exceptions and is used elsewhere in VTK. At same time I cleaned up the delete.
notes about the old approach: catch std::exception (json::RuntimeErrror's grandparent) succeeds typeid(e).name is vtkjson::RunttimeError (mangled) typeid(e) == typeid(a manufactures json::RuntimeError) succeeds dynamic_castjson::RuntimeError fails
Backport: paraview/release
Edited by David E. DeMarle