Enable setting a rule to define, if a field is required

[ClemensLinnhoff]

Describe the feature

Currently, a warning is given for all missing field. However, because it a lot of cases it does not make sense to fill every field. For example, in a sensor_view for a lidar sensor model, it does not make sense to output a warning, that the field "radar_sensor_view" is empty. But in that case I would still like to give a warning, if the (in this particular case) required field "lidar_sensor_view" is set.

Describe the solution you would like

Enable setting a rule "is_required" for specific field. This rule depends on the use case and cannot be automatically generated from the documentation in the proto files. (Unless some fields will be officially made mandatory in any case, as proposed in this issue: OpenSimulationInterface/open-simulation-interface#750)

Describe alternatives you have considered

Alternatively, I would remove the warning about empty fields at all, as there will most likely never be a case, where all existing fields in the entire interface are set.

Describe the backwards compatibility

It will break the behavior, that a warning is generated for every "missing" field. So there might be some backwards compatibility issues.

[ClemensLinnhoff]

There are already field marked as mandatory in OSI, e.g. https://opensimulationinterface.github.io/osi-antora-generator/asamosi/V3.5.0/gen/structosi3_1_1TrafficAction_1_1ActionHeader.html#ab7266e5a5270ce51d00a861c276956c8

But this should not just be a note, this should be a rule that can be tested.