Add max field to gdf returned from get_metrics

[kvanwerkhoven]

For post event dashboard 2, I need the maximum value of primary and secondary data for all value_times included in the query:
primary_max:
secondary_max:

I also need the sum of all values, but can calculate from the average. If for any reason the sum would NOT reliably equal the average x count, than also include primary_sum and secondary_sum

[kvanwerkhoven]

Reminder to also add 'measurement_units' to all query outputs

[mgdenno]

Reminder to also add 'measurement_units' to all query outputs

@kvanwerkhoven in the short term any field you add to group by will be added to output. This is all we will do in the query (at least the metric ones) because you can't add a field that you don't group_by.

[kvanwerkhoven]

Ah, OK. I thought that would cause it to group all the locations as one 'pool' for metrics calcs since measurement_units are the same for all locations