OARIS3 — plot_association_type relationship to sensor_track_type incorrect

The relationship between plot_association_type and sensor_track_type should be a composition such that the sensor track contains a collection of plot_association_type objects rather than a collection of references which can not be resolved as the plot_association_type does not have an id and is not published separately on another topic.

change plot_association relationship to composition

change the sensor_track_type to be a compostion of plot_association_types