New subject dataModels.MachineLearning and 3 data models

There is a new subject dataModel.MachineLearning and three data models.

• MLModel. Data model for compilation of the elements of a machine learning model.
• MLProcessing. Data model for compilation of the elements about the execution of a machine learning model.
• SubscriptionQuery. Subscription Query model for Machine Learning models

They are located on the CrossSector domain.

Thanks to the FIWARE4Water project.