Add tally consistency check for in OpenMCProblem

[pshriwise]

It is expected that the cell/mesh tally in the OpenMCProblem encompasses all fissionable material in the problem in a non-overlapping manner. To check that this is true, we can add a global kappa-fission tally to the OpenMC problem and check that the sum of the tallies used in transfers equals this global tally value. This provides an extra check for users to ensure that the tallies have been setup correctly.