In content/action we need to use information from $#collection_attributes[]
Be consistent in use of the base datatype name '_data_smile_object_relation_list_'

In edit template the base  '_data_object_relation_list_' was used.
Handle IsRequired and IsInformationCollector in same way as other datatypes.

If it's an information collector, when editing the object, don't cause
an error if there are no relations selected.

But in a form (view) if IsRequired is set then an error should be thrown.