Architect - lazily loaded menu item without list entity

Architect allows to store a lazily loaded menu item (ListDataStructure is set) without specifying list entity. This result in server error “object reference not set” without any further explanation. Architect shouldn’t allow to store such item without specifying list entity.

I reclassified this as a feature as it adds a new model integrity check. Will only merge it to master (2023.2).