Add a schema constraints option to graph of the gods load

GraphOfTheGods is used for most of our examples and lets people see features as well as interact with them more easily. We currently have options to load GraphOfTheGods without a mixed index and I would like to see similar parameters that load it with some schema constraints in place. I'm not that familiar with schema constraints and I'm hoping either @farodin91 or @FlorianHockmann would be able to provide guidance on how this would look.

From my perspective it's also a dependancy for adding schema constraints to the printSchema commands as currently duplicated effort would have to be made to develop and test the coverage enhancement.

Start by locating the GraphOfTheGods load options and the printSchema commands referenced in the issue. Review the existing option for loading without a mixed index, then seek maintainer guidance on which schema constraints should be included. Done means the load supports the agreed constraints and coverage can be added to printSchema without duplicated setup.

Written by the indexing model from the issue text.