Modifications to the new N_state_model.test_CaM_IQ_tensor_fit system test.
The system test now checks all of the optimised values to make sure the correct values have been
found. That will block any future regressions in this N-state model code path. The system test is
now also faster. And the pcs.structural_noise user function RMSD value has been set to 0.0 so that
the test no longer has a random component affecting the final optimised values.
