Number of observations not displayed in the overview for some dataflows
In Data Explorer, when landing on the overview in visualization, a data query with blank data selection and "values=0-0" range header is made in order to retrieve all relevant attributes single values and also retrieve the total number of observations, if the information cannot be retrieved trough the structure content constraints annotations. Currently this mechanism is broken as when testing with dataflows from OECD-v7-prod dataspace, where number of observations is not returned in content constraints, it is not retrieved neither through the blank data request