EPIC: as a data analyst I would like to manage in an optimal way the same data types which have different measurement units

[rcavaliere]

Linked to issue noi-techpark/bdp-commons#235

We must decide how to handle situations in which we get data related to the same data types but expressed with different measurement units. Shall we have different data types in the core or apply the logic to convert the data at a Data Collector side in the corresponding measurement unit associated to the (unique) data type we consider?