FGeometryCollection::MatchOptionalDefaultAttributes

Virtual helper function called by CopyMatchingAttributesFrom; adds attributes 'default, but optional' attributes that are present in InCollection This is used by [FGeometryCollection](API\Runtime\Chaos\GeometryCollection\FGeometryCollection) to make sure all UV layers are copied over by [CopyMatchingAttributesFrom()](API\Runtime\Chaos\GeometryCollection\FManagedArrayCollection\CopyMatchingAttr-)