PyMechanical workflow: cannot post-process inside Mechanical

[greschd]

When using the PyMechanical workflow (tested for shells), post-processing with the Composite Failure Tool inside Mechanical fails.

This may be fixable by adjusting the paths used in the workflow. Otherwise, the limitation needs to be documented.

Looking at the path above, it could also be an issue specific to running Mechanical from a different drive than the data is stored on: the D:/:/ component in this path should be C:\.

[greschd]

Reported as an issue on the backend; will document the limitation here.