Description

As for the mockup.
The counter widget should provide an aggregated (sum, avg, min, max...) value about an attribute, like this:

Issues

• Implement Geodashboard #2622
  Acceptance criteria:
• the counter must be present on both dashboard and map contexts, with map sync as for the charts.
• counter creation/editin wizard should allow to configure a variable, the aggregation function to use and optionally a filter for the data to use. It allows also to confiugre the unit of measure to show