Issue: When new expansions launch, old spells get removed and as a consequence the ClassIcon module will throw errors for the corresponding Spell IDs.

TODO: We can manually remove the no longer existing spells from the tables in the Data file for the new expansion, but users may have added their own custom auras via Spell ID in the ClassIcon module GUI. We probably should remove invalid Spell IDs from the db in the ClassIcon module if no corresponding spell can be found (and show an appropriate warning message in the chat to the user).