FAQLists crash and burn without a default FAQList

The current implementation of FAQLists is somewhat WIP. We could fix this with a fixture, but better would be to make a more robust implementation.

For example, FAQLists are currently constructed at load-time, for every question instantiated by the blueprint. FAQs aren't needed before rendering the actual question, so we could postpone construction until then at least. This provides an opportunity to fail gracefully.

Then finally a default fixture with a custom error message if it's not loaded as the cherry on top.