[ctml_writer] Improve error reporting
[ctml_writer] Improve error reporting

Print a more useful traceback for cases where exceptions are raised in ctml_writer.

imitrichev/cantera,imitrichev/cantera,imitrichev/cantera,Heathckliff/cantera,Heathckliff/cantera,Heathckliff/cantera,Heathckliff/cantera,Heathckliff/cantera,imitrichev/cantera,imitrichev/cantera,Heathckliff/cantera,imitrichev/cantera