Add tests for iconTag parameter in entity-types create

[jeff-schnitter]

Summary

The Cortex API for creating entity types now supports an optional iconTag parameter (see API docs).

Tasks

• Modify existing entity-types create test to include a valid iconTag (Cortex-builtin::Basketball)
• Add test to verify behavior when an invalid iconTag is provided (API uses default icon, does not fail)
• Verify tests pass

Notes

• The API does not reject invalid iconTag values - it simply uses a default icon
• Tests should verify this behavior to catch any future API changes