From the variable naming system, return the model type. Model types are custom names that are easier to understand than the usual component-measure pairing. For example, site index models would be called "stem height models" hecause the component is the stem and the measure is the height. However, site index models need a special name. Model types are these names. If a model type is not defined, the component-measure pairing is used instead.
get_model_type(response_name)The response_name from the variable naming system.