Extension of the ruleset: is_equal_to

[jdsika]

In this issue we encountered the situation that the host_vehicle_id was not set in the ground truth. The validation should catch the unset field but we should think about extending the rule is_equal_to to be able to reference other fields because the host_vehicle_id should be the same in ground truth and in sensor view.

[asadekasam]

OSI/QC Project 2025.09.30: Issue is valid but not urgent and potentially involves larger in architecture and rules syntax. It shall be conisdered for a later release (after 3.8.0)