Field charts for non-numeric fields #4182
Up until now, trying to generate a field chart on a non-numeric value failed, as the server did only try to calculate statistical aggregations for the field and that is not possible. Anyway, we could still calculate the total and cardinality functions for those fields, as we do in the statistics analyzer.
This PR changes how we treat non-numeric field charts, enabling users to generate graphs for cardinality and total. It is as well possible to stack them to other field charts, and add them to dashboards, just as with any other field graphs.