WAB chart widget - show count of values

[XabierVelasco_Echeverría]

Current situation: the chart widget in WAB can be configured to show the count of features by category. In one of the last releases it was added new functionality to include the labels of each category into the chart. In the other hand, if the user wants to know the exact count (and percentage), it must click on each part of the chart yet.

Improvement requested: allow users to define in the configuration of the chart whether count and percentage values should be shown by default on the chart as part of the labels, without user clicking.