Updating simulation data when of CST templates children are updated

[qualand]

Current implementation does not update CST template children (i.e., facets) within simulation data when facets are re-created.

The issue is due to template children get dumped and regenerated with new pointers.

Couple of options:

• Update template setters to update children based on the parameter being set, e.g., focal length. This can get complicated for other parameters (i.e., gaps) where it would be better to re-build children from scratch.
• Add errors when a parameter cannot be updated without rebuilding simulation data.

Questions to answer:

• How will simulation data be updated or re-built before a simulation?